Image Cyclohexane chair colour coded 3D balls.png 250px thumb A cyclohexane molecule in chair conformation .... A cyclohexaneconformation is any of several three dimensional shapes that a cyclohexane molecule ... character remains the same. In cyclohexane, the two chair conformations have the same energy. At 25 C, 99.99 of all molecules in a cyclohexane solution will be in a chair conformation. In cyclohexane ... a molecule of cyclohexane in the twist boat conformation can achieve the chair conformation again .... Twistane is another compound with a forced twist boat conformation. Cyclohexane derivatives Substituents ... of cyclohexane do exist that have a more stable twist boat conformation. An example is 1,2,4,5 ... the twist boat conformation actually dominates. Also in cyclohexane 1,4 dione with the steric ... successive bonds in a carbon chain is about 109 degrees. Therefore the cyclohexane ring tends ... J. year 2011 title Toward Consistent Terminology for Cyclohexane Conformers in Introductory Organic ... form. Cyclohexane conformations have been extensively studied in organic chemistry because they are the classical ... and chemical properties of cyclohexane. Historical background In 1890, Hermann Sachse , a 28 year old assistant in Berlin, published instructions for folding a piece of paper to represent two forms of cyclohexane ... and Odd Hassel shared the 1969 Nobel Prize for work on the conformations of cyclohexane and various other molecules. General The carbon carbon bonds along the cyclohexane ring are sp orbital hybridisation ... particular conformation of the carbon ring, the directions of the 12 carbon hydrogen bonds and therefore ... atoms lie on the same plane. These shapes are called half chair conformations. Chair conformation ... chair conformation, the carbons C1 through C6 alternate between two parallel planes, one with C1 ... in opposite senses relative to the symmetry axis. Thus, in a chair conformation, there are three C ... of the substituents. For example, in methylcyclohexane the lowest energy conformation is a chair ... more details
are perpendicular to the plane axial . This conformation allows for the most stable structure of cyclohexane. Another conformation of cyclohexane exists, known as boat conformation , but it interconverts ... more stable Chemical structure conformation . Cyclohexane has the lowest angle and torsional ... left A cyclohexane molecule in chair conformation. Hydrogen atoms in axial positions are shown in red ...chembox verifiedrevid 443679934 name Cyclohexane ImageFileL1 Cyclohexane 2D skeletal.svg ImageSizeL1 80px ImageNameL1 Cyclohexane ImageFileR1 Cyclohexane 3D space filling.png ImageSizeR1 100px ImageNameR1 3D structure of a cyclohexane molecule ImageFileL2 Cyclohexane chair 2D stereo skeletal.png ImageSizeL2 100px ImageNameL2 Skeletal formula of cyclohexane in its chair conformation ImageFileR2 Cyclohexane chair 3D balls.png ImageSizeR2 100px ImageNameR2 Ball and stick model of cyclohexane in its chair conformation Section1 Chembox Identifiers ChEBI Ref ebicite correct EBI ChEBI 29005 DrugBank Ref ... Cyclopentane br Cycloheptane OtherCpds Cyclohexene br Benzene Cyclohexane is a cycloalkane with the molecular formula Carbon C sub 6 sub Hydrogen H sub 12 sub . Cyclohexane is used as a nonpolar ... scale, cyclohexane is produced by reacting benzene with hydrogen . Because of its unique chemical and conformational properties, cyclohexane is also used in labs in analysis and as a standard. Cyclohexane has a distinctive detergent like odor, reminiscent of cleaning product in which it is sometimes used . Structure and physical properties Conformation main Cyclohexaneconformation The 6 vertexed ring does not conform to the shape of a perfect hexagon . The conformation of a flat 2D planar ... torsional strain would also be considerable because all of the bonds would be Eclipsed conformation eclipsed bonds . Therefore, to reduce torsional strain , cyclohexane adopts a three dimensional structure known as the chair conformation . This was first proposed as early as 1890 by Hermann Sachse ... more details
wiktionary conformation conformational conformations Conformation generally means structural arrangement and may refer to Conformational isomerism , a form of stereoisomerism in chemistry Carbohydrate conformationCyclohexaneconformation Protein conformationConformation activity relationship between the biological activity and the conformation or conformational changes of a biomolecule Animal breeding Equine conformation evaluates the degree of correctness of a horse s bone structure, musculature, and its body proportions Conformation dog to a particular dog breed Conformation show , a dog show in which dogs are judged according to how well they conform to the established breed type See also Conformable Conformal disambiguation Conformality Conformance disambiguation Conformer Confirmation Conformity disambig ar fa ... more details
For the geometry of staggered rows lattice group context date March 2011 Image Staggered Conformation.svg thumb 200px Staggered conformation image right in Newman projection Image Eclipsed Conformation.svg 200px thumb Eclipsed conformation Image Ethane conformation.gif thumb right 200px conformational freedom in ethane In organic chemistry, a staggered conformation is a chemical conformation of an ethane like moiety abcX Ydef in which the substituents a,b,and c are at the maximum distance from d,e,and f. This requires the torsion angles to be 60 . ref Ernest L. Eliel and Samuel H. Wilen, Stereochemistry of Organic Compounds , Wiley 1994 , p.1207 ref Such a conformation exists in any open chain single chemical bond connecting two sp sup 3 sup orbital hybridisation hybridised atoms, and is normally a conformational energy minimum .For some molecule s such as those of n butane , there can be special versions of staggered conformations called gauche and anti see first Newman projection diagram in Conformational isomerism . See also Alkane stereochemistry References Reflist DEFAULTSORT Staggered Conformation Category Stereochemistry ar nl Geschrankte conformatie sr Stepeni asta konformacija sv Staggered ... more details
Conformation in dogs refers solely to the externally visible details of a dog s structure and appearance, as defined in detail by each dog breed s written Breed standard dogs breed standard . A dog that conforms to most of the items of description in its individual breed standard is said to have good conformation . Unlike equine conformation , there are no fixed rules for dog conformation, as dogs are the most variable in appearance of any animals Phenotypic variation among dog breeds, whether it be in size, shape, or behavior, is greater than for any other animal ref http www.bio medicine.org biology news Scientists fetch useful information from dog genome publications 2118 1 Scientists fetch useful information from dog genome publications, Cold Spring Harbor Laboratory, December 7, 2005 published online in Bio Medicine ref . Instead, conformation in dogs is based on the dog type from which the breed developed, along with many details that have been added to the breed standard for purposes of differentiation from other breeds, for working reasons, or for enhancing the beauty of the animals from the viewpoint of the fanciers who wrote the breed standards. Breed standards The breed standard for each breed of dog details desirable and undesirable attributes of appearance and temperament for an individual breed. Due to the great variability in dogs, there is no one standard of good conformation. What is good conformation for a lapdog will not be good conformation for a guard dog good leg structure for a dog that must travel long distances will not be the same as good leg structure for dogs whose conformation requires short bursts of speed. Breed standards are designed solely to describe the breed s history and purpose, temperament, and appearance. The breed standard is not a checkbox ... agricultural department rules. Conformation refers solely to the externally visible details ... good conformation for a particular breed, see the article about that specific breed of dog ... more details
refimprove date January 2012 Carbohydrate conformation refers to the overall three dimensional structure adopted by a carbohydrate saccharide molecule as a result of the through bond and through space physical forces it experiences arising from its molecular structure . The physical forces that dictate the three dimensional shapes of all molecules here, of all monosaccharide , oligosaccharide , and polysaccharide molecules are sometimes summarily captured by such terms as steric interactions and stereoelectronic effects see below . Saccharide and other chemical conformations can be reasonably shown using two dimentional structure representations that follow set conventions these capture for a trained viewer an understanding of the three dimensional structure via structure drawings see organic chemistry article, and 3D Representations section in molecular geometry article they are also represented by stereogram s on the two dimensional page, and increasingly using 3D display technologies on computer monitors. Formally and quantitatively, conformation is captured by description of a molecule ... with and recognition by other molecules processes which in turn can alter conformation . Chemical transformations and biological signalling mediated by conformation dependent molecular recognition ... date January 2012 Conformations of Carbohydrates Monosaccharide Conformation Unsourced image removed ... image caption 1 Friday, 7 August 2009 date January 2012 Conformational Analysis Chair conformation ... stable conformer. Since there are two possible chair conformation steric and stereoelectronic ... when determining a preferred conformation Conformations of five membered rings are limited to two, envelope and twist. The envelope conformation has four atoms in a plane while the twist form ... anomeric effect. Hydroxymethyl Conformation Deleted image removed Image Hydroxymethyl conformations.png ... Conformation In addition to the factors affecting monosaccaride residues, conformational ... more details
Terrier to be presented. A conformation dog show is not a comparison of one dog to another but a comparison ... large numbers of breeds. The first modern conformation dog show was held in Newcastle upon Tyne ..., where there are usually a few conformation classes for Purebred pedigree dogs, and several novelty ... are optional. ref cite web url http www.akc.org events conformation beginners.cfm title A Beginner ... events conformation counting points.cfm title Points Schedule author American Kennel Club ref At least ... of dogs competing. ref name AKCPoints cite web url http www.akc.org events conformation counting ... and organized by the Association Colombian Kennel Club lang es Asociacion Club Canino Colombiano . Their conformation ... by the F d ration Cynologique Internationale for international championships in conformation ... ref Criticism of dog showing see also Pedigree Dogs Exposed The practice of breeding dogs for conformation showing has become a subject of intense debate. Some critics state that conformation shows ... at dog shows. See also Championship dog Conformation dog List of dog sports Junior Showmanship Dog ... and breed standards Canadian Veterinary Journal Dog nav Dog sports DEFAULTSORT Conformation ... more details
Equine conformation evaluates the degree of correctness of a horse s bone structure, musculature, and its body proportions in relation to each other. Undesirable conformation can limit the ability to perform a specific task. Although there are several universal faults, a horse s conformation is usually ... considered in judging conformation. A horse with poor form for a Grand Prix show jumper could have excellent conformation for a World Champion Cutting sport cutting horse , or to be a champion draft horse . Every horse has good and bad points of its conformation and many horses including Olympic caliber horses excel even with conformation faults. see also Equine anatomy Conformation of the head ... 03 accessdate 2008 03 08 ref The relationship between head conformation and performance are not well ... issue 6 pages 1849 1854 accessdate 2008 03 09 quote pmid 8847243 ref These factors suggest that the conformation ... crest due to obesity or insulin resistance can be treated with a reduced diet. Conformation ... can be determined by looking at the point of shoulder to the point of elbow. Conformation of the Ideal ... degrees Conformation Should not turn out or in and should sit squarely on the forearm. the olecrannon ... and twist the leg. This conformation will make the horse toe out. They tend to wing in when the knee .... Out Turned Elbow Usually associated with base narrow and pigeon toed conformation. The legs are too .... The Forearm radius Connects the elbow and knee Conformation Should be in perfect line with the knee ... of endurance and stamina. A horse that will do slow, steady work might not be hampered by chest conformation ... the front legs and hindquarters. Conformation A horse s chest is measured from the bottom end of the neck ... on speed and agility All information is derived from The horse Conformation Handbook written by Heather ..., and spins needed by stock horses. This conformation quality is most useful in Quarter Horse racing ... turns. Conformation of the body Withers File Yeguacriolla.jpg right thumb Mutton withers. Mutton ... more details
thumb 797px left log sub 10 sub of Cyclohexane vapor pressure. Uses formula math scriptstyle ... center colspan 3 Vapor liquid Equilibrium br for Cyclohexane Ethanol ref name cheric b Cite web ... colspan 3 Vapor liquid Equilibrium br for Cyclohexane Benzene ref name cheric b br P 760 mm Hg ... bc C0C090 bgcolor D0D0D0 align center colspan 3 Vapor liquid Equilibrium br for Cyclohexane hexane ... align center colspan 3 Vapor liquid Equilibrium br for Cyclohexane Acetic acid ref name cheric ... 3 Vapor liquid Equilibrium br for Cyclohexane Isopropanol ref name cheric b br P 760 mm Hg chembox header rowspan 2 BP br Temp. br C colspan 2 by mole cyclohexane chembox header liquid vapor 78.71 .... Use dmy dates date September 2010 DEFAULTSORT Cyclohexane Data Page Category Chemical data pages ... more details
Conformation activity relationship is the relationship between the biological activity and the Chemical structure conformation or conformational change s of a biomolecule. This terminology emphasizes the importance of dynamic conformational changes for the biological function, rather than the importance of static three dimensional structure used in the analysis of structure activity relationship s. ref cite journal last1 Taylor first1 RE last2 Chen first2 Y last3 Beatty first3 A last4 Myles first4 DC last5 Zhou first5 Y title Conformation activity relationships in polyketide natural products a new perspective on the rational design of epothilone analogues journal Journal of the American Chemical Society volume 125 issue 1 pages 26 7 year 2003 pmid 12515494 doi 10.1021 ja028196l ref The conformational changes usually take place during Binding molecular intermolecular association , such as protein protein interaction or Protein ligand protein ligand binding . A binding partner changes the conformation of a biomolecule e.g. a protein to enable or disable its biochemical activity. Methods for analysis of conformation activity relationship vary from in silico ref cite journal last1 Carotenuto first1 Alfonso last2 D ursi first2 Anna Maria last3 Mulinacci first3 Barbara last4 Paolini first4 Ilaria last5 Lolli first5 Francesco last6 Papini first6 Anna Maria last7 Novellino first7 Ettore last8 Rovero first8 Paolo title Conformation Activity Relationship of Designed Glycopeptides as Synthetic Probes for the Detection of Autoantibodies, Biomarkers of Multiple Sclerosis journal Journal of Medicinal Chemistry volume 49 pages 5072 9 year 2006 doi 10.1021 jm060117j issue 17 pmid 16913697 ref or using experimental methods such as X ray crystallography and NMR where the conformation before and after activity can be compared statically or using dynamic methods such as dual polarisation ... references using ref ref tags which will then appear here automatically Reflist DEFAULTSORT Conformation ... more details
Cleanup date February 2009 Image Chromosome Conformation Capture Technology.jpg thumb 400px Chromosome Conformation Capture Technologies Chromosome conformation capture , ref cite journal author Dekker J, Rippe K, Dekker M, Kleckner N year 2002 title Capturing chromosome conformation journal Science volume 295 pages 1306 1311 pmid 11847345 doi 10.1126 science.1067799 issue 5558 ref or 3C , is a high throughput molecular biology technique used to analyze the organization of chromosomes in a cell s natural state. Studying the structural properties and spatial organization of chromosomes is important for the understanding and evaluation of the gene regulation regulation of gene expression , DNA replication and DNA repair repair , and Genetic recombination recombination . One example of chromosomal interactions influencing gene expression is a chromosomal region which can fold in order to bring an Enhancer genetics enhancer and associated transcription factor s within close proximity of a gene, as was first shown in the beta globin locus. ref cite journal author Tolhuis B, Palstra RJ, Splinter ... S1097 2765 02 00781 5 issue 6 ref Chromosome conformation capture has enabled researchers to study ... version of 4C enhanced 4C , 3 5C and 3D assays and 4 Genome conformation capture GCC related Hi ... brought the assessment of chromosome interactions to the genome wide scale. Chromosome Conformation ... G, de Laat W, Forn T year 2007 title Quantitative analysis of chromosome conformation capture assays ... 7 ref Circularized Chromosome Conformation Capture 4C The 4C strategy ref cite journal author Zhao ... U, Pant V, Tiwari V, Kurukuti S, Ohlsson R year 2006 title Circular chromosome conformation capture ... conformation capture on chip 4C journal Nat. Genet. volume 38 pages 1348 1354 pmid 17033623 ... enzyme used in step 2. Carbon Copy Chromosome Conformation Capture 5C The 5C technique ref cite ... Conformation Capture Category Chromosomes ... more details
Single strand conformation polymorphism SSCP , or single strand chain polymorphism, is defined as conformational difference of single stranded DNA nucleotide sequences of identical length as induced by differences in the sequences under certain experimental conditions. This property allows to distinguish the sequences by means of gel electrophoresis , which separates the different conformations. Physical background A single nucleotide change in a particular sequence, as seen in a double stranded DNA, cannot be distinguished by electrophoresis, because the physical properties of the double strands are almost identical for both alleles. After denaturation, single stranded DNA undergoes a 3 dimensional folding and may assume a unique conformational state based on its DNA sequence. The difference in shape between two single stranded DNA strands with different sequences can cause them to migrate differently on an electrophoresis gel, even though the number of nucleotides is the same, which is, in fact, an application of SSCP. Applications in molecular biology SSCP used to be a way to discover new DNA polymorphisms apart from DNA sequencing, but is now being supplanted by sequencing techniques on account of efficiency and accuracy. These days, SSCP is most applicable as a diagnostic tool in molecular biology. It can be used in genotyping to detect homozygous individuals of different allelic states, as well as heterozygous individuals that should each demonstrate distinct patterns in an electrophoresis experiment. SSCP is also widely used in virology to detect variations in different strains of a virus, the idea being that a particular virus particle present in both strains will have undergone changes due to mutation, and that these changes will cause the two particles to assume ... Societies, 21 May 2009. ref References references DEFAULTSORT Single Strand Conformation ... de conformation des simples brins ja SSCP pt Polimorfismo de conforma o de filamento nico uk ... more details
orphan date January 2011 Asteranes are members of a series of cage hydrocarbons that feature the boat conformation of cyclohexane as a defining structural element. ref Henning Hopf, Classics in Hydrocarbon Chemistry, Wiley VCH, New York, 2000, pages 34 37, ISBN 978 3527296064. ref They can be considered as homologues of the prismanes in which each edge has been replaced by a bridging methylene group . References reflist Category Hydrocarbons ... more details
File Ring Flip.png 450px right thumb Ring Flip Ring flipping also known as ring inversion or ring reversal is a phenomenon involving the interconversion by rotation about single chemical bond bonds of cyclic conformer s having equivalent ring shapes but not necessarily equivalent Three dimensional space spatial positions of substituent atom s. The six membered ring of the alkane , cyclohexane , has the chair as its preferred conformation and through proton Nuclear Magnetic Resonance NMR it would be expected that the produced spectrum would show the different sorts of protons axial and equatorial resonating at different frequency frequencies , and so two Wiktionary signal signals would be seen, due to the protons being in slightly different chemical environments. However, only one signal can be seen as the two isomers are rapidly interconverting. This also occurs with monosubstituted cyclohexanes. This changes with the use of low temperature , as the two isomers visible interconvert much more slowly than at room temperature. When cyclohexane undergoes a ring inversion, all axial bonds become equatorial, or vice versa. The half chair conformation is the energy maximum when proceeding from the chair to the twisted boat conformation. The true boat conformation is the energy maximum for the interchanging of the two mirror image twist boat conformers, the second of which is converted to the other chair confirmation through another half chair. However, the chemical reactivity chemistry reactivity of cyclohexane, is inconsistent with two types of hydrogens in a stable form of the molecule for example, there is only one monochlorocyclohexane, not two, as would be predicted if axial and equatorial hydrogens could be replaced independently , but this is due to the presence of rapid ring inversion as explained above. In substituted cyclohexanes, electrostatic repulsion steric repulsion can be minimised by the substituents occupying positions along the equatorial Plane mathemati ... more details
of the cyclohexane ring. Like all substituted cyclohexanes, it can ring flip rapidly between two Cyclohexaneconformation chair conformations . However, a monosubstituted Methylcyclohexane exists almost ... pair contributing approximately 7.61 kJ mol strain. However, the equatorial conformation experiences no such interaction so it is more stable. Disubstituted cyclohexanes Main Cyclohexaneconformation Cyclohexanes could also have more than one methyl branch. Disubstituted cyclohexane, or also known as dimethylcyclohexane has two methyl branches. Unlike the monosubstituted cyclohexane, there are several ... carbons of the cyclohexane, with one of them axial and the other equatorial, there would be a gauche ... and the other equatorial. It would have the same total strain energy as the monosubstituted cyclohexane ... more details
usually take a more linear conformation to avoid the steric strain between the substituents. ref name Anslyn 1,3 diaxial strain Main Cyclohexaneconformation 1,3 diaxial strain is another form of strain ... of a cyclohexane ring and a hydrogen at the Arene substitution patterns meta position. When the substituent is cyclohexaneconformation axial , it is brought near to an axial meta hydrogen ... be held in an energetically unfavorable conformation by the Chemical bond bonds within that molecule. Without the bonds holding the conformation in place, the strain energy would be released. Summary ... strained, higher energy molecular conformation will spontaneously convert to the lower energy molecular conformation. Image Anti and Gauche Butane.png thumb right upright 1.2 alt Examples of the anti ... for determining a more stable molecular conformation. ref name Anslyn While there are different ... anti and gauche . The anti conformation is more stable by 0.9 kcal mol. ref name Anslyn We ... possible gauche conformations and only one anti conformation. Therefore, entropy makes a contribution of 0.4 kcal in favor of the gauche conformation. ref name Coxon Coxon and Norman, Principles of Organic ... molecular strain Image Cyclohexane and methylcyclopentane.png thumb left upright 1.4 alt Images of cyclohexane and methylcyclopentane. Images of cyclohexane and methylcyclopentane. The standard enthalpy ... be attributed to strain. For example, H sub f sub sup o sup for cyclohexane is 29.9 kcal mol while ... Despite having the same atoms and number of bonds, methylcyclopentane is higher in energy than cyclohexane ... is absent in cyclohexane. Experimentally, strain energy is often determined using heat of combustion ... into a gauche conformation, one of which is 3 kcal mol higher in energy than the other. ref name Anslyn ... assumes a cyclopentane cyclopentane like conformation where the two terminal methyl groups ... the other chair conformation which puts the substituent in an equatorial position. The difference ... more details
of butane gallery Cyclohexane conformations Certain conformations of cyclohexane and other small ring compounds can be shown using a standard convention. For example, the standard Cyclohexaneconformation Chair conformation chair conformation of cyclohexane involves a perspective view from slightly above the average plane of the carbon atoms and indicates clearly which groups are Cyclohexaneconformation Chair conformation axial and which are Cyclohexaneconformation Chair conformation equatorial ... Beta D Glucose.svg Chair conformation of beta D Glucose gallery Haworth projection The Haworth projection ... eclipsed conformation. Nonetheless, the Fischer projection is a simple way of depicting multiple sequential stereocenters that does not require or imply any knowledge of actual conformation ... more details
measurements of a monosubstituted cyclohexaneconformationcyclohexane ring. ref name PACGlossary ... found in this conformation of ethyl cyclohexane, which amounts to approximately 2.7 kcal mol ... author Muller, P issue 5 ref Substituent s on a cyclohexane ring prefer to reside in the equatorial position to the axial. The difference in Gibbs free energy G between the higher energy conformation axial substitution and the lower energy conformation equatorial substitution is the A value for that particular substituent. Utility A values help predict the conformational isomerism conformation of cyclohexane rings. The most stable conformation will be the one which has the substituent or substituents equatorial. When multiple substituents are taken into consideration, the conformation where ... substituent therefore the most stable conformation has the tert butyl in the equatorial position. The utility of A values can be generalized for use outside of cyclohexane conformations. A values can ... contribute approximately 8 kcal mol to the enthalpic term making this conformation unrealistically high ... sigma math Where is equal to the number of micro states available for each conformation. image ax pos.jpg thumb 350px center Possible axial conformations of ethyl cyclohexane. image eq pos.jpg thumb 500px center Possible equatorial conformations of ethyl cyclohexane. Due to the larger number of possible conformations of ethyl cyclohexane, the A value is reduced from what would be predicted based ... catalyst. The large tBu group used locks the conformation of each molecule placing it equatorial ... chair conformations and the favorable hydrogen bond available in the conformation where both hydroxyl substituents are equatorial Limitations A Values are measured using a mono substituted cyclohexane ... the axial conformation. image CarboxylicAcidChairFlip.png thumb 400px center Equilibrium ... more details
In chemistry , epimers are diastereomers that differ in configuration of only one stereogenic center . Diastereomers are a class of stereoisomers that are non superposable, non mirror images of one another. ref March, Jerry and Smith, Michael B.. March s Advanced Organic Chemistry Reactions, Mechanisms and Structure . 6th ed. Hoboken, NJ momo peon & Sons, Inc., 2007. ref ref GoldBookRef title epimers file E02167 ref In chemical nomenclature, one of the epimeric pairs is given the prefix epi for example in quinine and epi quinine . When the pairs are enantiomers , the prefix becomes ent . Examples The sugar s glucose and glucose are epimers. In glucose, the OH group on the first anomeric carbon is in the direction opposite the methylene group on carbon C 6 in the Cyclohexane conformation Chair conformation axial position . In glucose, the OH group is oriented in the same direction as the methylene group in the equatorial position . ref http www.biotopics.co.uk as glucose2.html Structure of the glucose molecule Bot generated title ref These two molecules are both epimers and anomers . class wikitable style margin 1em auto 1em auto Image Alpha D glucopyranose 2D skeletal.png 220px Image Beta D glucopyranose 2D skeletal.png 220px align center center small D small glucopyranose center center small D small glucopyranose center D glucopyranose and D mannopyranose are epimers because they differ only in the stereochemistry at the C 2 position. The hydroxyl group in D glucopyranose is equatorial in the plane of the ring while in D mannopyranose the C 2 hydroxyl group is Cyclohexane conformation Chair conformation axial up from the plane of the ring . These two molecules are epimers but not anomer s. class wikitable style margin 1em auto 1em auto File Beta D glucopyranose.svg 200px File Beta D mannopyranose.svg 200px align center center small D small glucopyranose center center small D small mannopyranose center Doxorubicin and epirubicin are two close ... more details
factor explaining this conformation is reduction in allylic strain by minimizing the dihedral ... reserved for the most bulky groups i.d. both arenes 1 The other contributing factor explaining this conformation ... more details
group axial on the ring, which is an unstable cyclohexaneconformation Protein rotamer libraries A rotamer ... gauche as well as the anti form are staggered conformation s In chemistry , conformational isomerism ... of conformational isomerism include Linear alkane conformation s with staggered, eclipsed and gauche conformers, and Ring conformationCyclohexaneconformation s with chair and boat conformers. Carbohydrate conformation Atropisomerism due to restricted rotation about a bond, a molecule can become ... distribution of lowest energy conformation in a two component equilibrating system at various ... system atropisomerism is especially prevalent, e.g. 1,1 Bi 2 naphthol binaphthol . In Cyclohexanecyclohexane ... called Fluxional molecule fluxional . Conformation dependent reactions Image E2 Elimination Reaction.png ... staggered conformation Image E2 14tBuchexCl.png right thumb 350px The trans ... not eliminate.The cis isomer is already in the correct geometry in its most stable conformation and therefor it eliminates easily. Reaction rates are highly dependent on the conformation of the reactants ... arrangement may not be attainable depending. Adjacent substituent s on a cyclohexane ring can achieve ... of freedom. Rotamer libraries usually contain information about both conformation and frequency of a certain conformation. Often libraries will also contain information about the variance about dihedral ... conformations or by dividing dihedral angle space into bins, and determining an average conformation ... about sp3 sp3 bonds into three 120 bins centered on each staggered conformation 60 , 180 , 60 . Rotamer ... depend on the local backbone conformation or not. Backbone independent rotamer libraries make no reference to backbone conformation, and are calculated from all available side chains of a certain ... present conformations and or frequencies dependent on the local backbone conformation as defined ... usually of 5 amino acids in length, where the central residue s side chain conformation is examined ... more details
chembox Verifiedfields changed Watchedfields changed verifiedrevid 424837516 Name Iceane ImageFileL1 Iceane 3D sticks.png ImageSizeL1 100px ImageFileR1 Iceane 3D vdW.png ImageSizeR1 100px IUPACName Tetracyclo 5.3.1.1 sup 2,6 sup 0 sup 4,9 sup dodecane OtherNames Wurtzitane Section1 Chembox Identifiers CASNo Ref cascite correct ?? CASNo 53283 19 5 RTECS ChemSpiderID Ref chemspidercite changed chemspider ChemSpiderID 26333278 SMILES C1C2CC3CC1C4CC2CC3C4 InChI 1 C12H18 c1 7 2 11 3 8 1 10 4 9 7 5 12 11 6 10 h7 12H,1 6H2 t7 ,8 ,9 ,10 ,11 ,12 InChIKey KZNNISMAUNEBPT KUDAMMAABM StdInChI Ref stdinchicite changed chemspider StdInChI 1S C12H18 c1 7 2 11 3 8 1 10 4 9 7 5 12 11 6 10 h7 12H,1 6H2 t7 ,8 ,9 ,10 ,11 ,12 StdInChIKey Ref stdinchicite changed chemspider StdInChIKey KZNNISMAUNEBPT KUDAMMAASA N Section2 Chembox Properties Formula C sub 12 sub H sub 18 sub MolarMass 163.56 g mol Appearance Density Solubility Solvent SolubleOther MeltingPt BoilingPt Viscosity Section3 Chembox Structure CrystalStruct Dipole Section7 Chembox Hazards ExternalMSDS MainHazards FlashPt RPhrases SPhrases Section8 Chembox Related Function OtherFunctn Iceane is a saturated hydrocarbon saturated polycyclic compound polycyclic hydrocarbon with formula C sub 12 sub H sub 18 sub . It has a Cage enclosure cage like molecule molecular structure, whose carbon skeleton can be viewed as three fused cyclohexane rings in the boat cyclohexane conformation conformation or as two such rings in the chair conformation, connected by three parallel bonds. The name iceane was proposed by the chemist Louis Fieser about a decade before the compound was first prepared. He was carrying out studies on the arrangement of water molecules in ice , when it occurred to him that there could exist a stable hydrocarbon with the above structure. Fact date November 2009 It is also referred to as wurtzitane , ref doi 10.1002 hlca.19750580522 ref due to its similarity to the wurtzite crystal structure ref doi 10.1071 CH9761721 ref h ... more details
wiktionary chair The term chair has a number of possible meanings Chair , piece of furniture Chair, type of carriage , also called riding chair Electric chair , execution device often known as just the chair Orchestra , musician s seating position Chair railway , a block supporting a rail on a sleeper Chair conformation , molecular structure of cyclohexane Chair acrobatics , various balancing circus skills The Chair game show , TV show hosted by John McEnroe Chair Entertainment , Aka. ChAIR, a video game developer based in Provo, Utah The Chairs , play by Eug ne Ionesco Chair Polish academic department a division of a university faculty devoted to a particular academic discipline The Chair Aintree Racecourse , a fence at Aintree Racecource that is best known for its use in the Grand National horse race Position Chair academic a professorship in a university The Master of Ceremonies is referred to as the Chair in some organizations List of Rival Schools characters Chairperson Chairperson Rival Schools , known as nihongo Iincho Iinch in Japan, is a character from the Rival Schools series of fighting games Chairperson , is the highest officer of an organized group disambig fr Chair ro Sp tar ... more details
Wikify date January 2012 Unreferenced date December 2009 The IUPAC defines pseudorotation as a conformational change resulting in a structure that appears to have been produced by rotation of the entire initial molecule and is superimposable on the initial one, unless different positions are distinguished by substitution or isotopic labeling. No angular momentum is generated by this motion this is the reason for the term. Formally it refers to symmetrical molecules, although the mechanism is invoked for low symmetry species also. A small displacement of the atomic positions leads to a loss of symmetry until the symmetric product forms. Although not formally required, pseudorotation normally involves displacements along low energy pathways. MX sub 5 sub compounds Main Berry mechanism The Berry mechanism refers to the facile interconversion of axial and equatorial ligand in MX sub 5 sub compounds, e.g. D3 sub h sub symmetric PF sub 5 sub Image Iron pentacarbonyl Berry mechanism.png center 550px Pseudorotation of Iron Pentacarbonyl Complex Berry mechanism Cycloalkanes Main Cyclohexane conformation The structural dynamics of cycloalkanes can be described as pseudorotations. Category Chemical bonding Category Stereochemistry Chemistry stub de Pseudorotation es Pseudorrotaci n fr Pseudorotation de Berry ... more details
conformations exist in cyclic alkanes see cyclohexaneconformation s. More on the impact of gauche ... to rotation around the C C bond. Two of these are recognised as energy minimum staggered conformation and energy maximum eclipsed conformation forms. The existence of specific conformations is due ... hindrance is minimised. The staggered conformation is more stable by 12.5 joule kJ mole unit mol than the eclipsed conformation, which is the energy maximum for ethane. In the eclipsed conformation the torsional angle is minimized. File Staggered and eclipsed.svg center 338px staggered conformation left, eclipsed conformation right in Newman projection center Image Ethane staggered depth cue 3D balls.png ... conformations are no longer equivalent and represent two distinct conformers the anti conformation left most, below and the gauche conformation right most, below . File Anti gauche.svg center 558px ... are free of torsional strain, but, in the gauche conformation, the two methyl groups are in closer ... for the existence of the energy maximum for an eclipsed conformation in ethane is steric hindrance ... for steric repulsion causing the staggered conformation of ethane. Weinhold, F. Angew. Chem. Int. Ed. 42, 4188 4194 2003 ref In the staggered conformation, one C H sigma bond sigma bonding orbital donates ... of this effect is maximized when the two orbitals have maximal overlap, occurring in the staggered conformation. There is no overlap in the eclipsed conformation, leading to a disfavored energy maximum ... the staggered conformation of ethane. Bickelhaupt, F.M. & Baerends, E.J. Angew. Chem. Int. Ed ... a specific conformation IUPAC Gold Book exist a torsion angle of 60 is called gauche ref Anslyn ... between 0 to 30 is called synperiplanar or syn or cis conformation sp a torsion angle between 30 to 90 ... more details
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