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A mixture of cis-decalin and CXB can simultaneously match optical index and density of PMMA. [1] Due to the moderate dielectric constant of CXB (ε = 7.9 [2]), PMMA acquires charges that can be screened by the addition of salt (e.g. tetrabutyl ammonium bromide), leading to a very good approximation of colloidal hard sphere. [3]
trans-1,3-Disubstituted cyclohexanes are like cis-1,2- and cis-1,4- and can flip between the two equivalent axial/equatorial forms. [ 2 ] Cis -1,4-Di- tert -butylcyclohexane has an axial tert -butyl group in the chair conformation and conversion to the twist-boat conformation places both groups in more favorable equatorial positions.
a torsion angle between 0° and ±30° is called synperiplanar (sp), also called syn-or cis-conformation a torsion angle between 30° to 90° and −30° to −90° is called synclinal (sc), also called gauche or skew [ 33 ]
Very often, cis–trans stereoisomers contain double bonds or ring structures. In both cases the rotation of bonds is restricted or prevented. [4] When the substituent groups are oriented in the same direction, the diastereomer is referred to as cis, whereas when the substituents are oriented in opposing directions, the diastereomer is referred to as trans.
Enoyl-CoA-(∆) isomerase (EC 5.3.3.8, also known as dodecenoyl-CoA-(∆) isomerase, 3,2-trans-enoyl-CoA isomerase, ∆3(cis),∆2(trans)-enoyl-CoA isomerase, or acetylene-allene isomerase, [1] is an enzyme that catalyzes the conversion of cis- or trans-double bonds of coenzyme A (CoA) bound fatty acids at gamma-carbon (position 3) to trans double bonds at beta-carbon (position 2) as below:
In chemistry, hexahydro-1,3,5-triazine is a class of heterocyclic compounds with the formula (CH 2 NR) 3. Known as aldehyde ammonias, these compounds characteristically crystallize with water . They are reduced derivatives of 1,3,5- triazine , which have the formula (CHN) 3 , a family of aromatic heterocycles.
The descriptors cis (lat. on this side of) [2] and trans (lat. over, beyond) [3] are used in various contexts for the description of chemical configurations: [4] [5] In organic structural chemistry, the configuration of a double bond can be described with cis and trans, in case it has a simple
(Similar procedures can give cis,trans isomers of 1,4-cyclooctadiene and 1,5-cyclooctadiene). [2] In addition, a photochemical method exists for the direct cis–trans isomerisation. Although this equilibrium strongly favours the more stable cis form, the reaction can be driven towards the trans form by trapping with silver ions. [11] [12]