当前位置: X-MOL 学术J. Struct. Chem. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
CHIRALITY-DEPENDENT HYDROGEN BONDING AND ENERGY OF 1-BENZYL-3-BROMO-5-HYDROXY- 4-[(4-METHYLPHENYL)SULFANYL]-1,5-DIHYDRO- 2Н-PYRROLE-2-ONE DIASTEREOMORPHS
Journal of Structural Chemistry ( IF 0.8 ) Pub Date : 2021-06-18 , DOI: 10.1134/s0022476621050097
D. P. Gerasimova , A. F. Saifina , D. V. Zakharychev , A. R. Zaripova , R. R. Fayzullin , A. R. Kurbangalieva , O. A. Lodochnikova

Abstract

Two crystalline diastereomorphs of rac-1-benzyl-3-bromo-5-hydroxy-4-[(4-methylphenyl)sulfanyl]-1,5-dihydro-2Н-pyrrole-2-one are obtained and characterized: the racemic compound (P21/c) and the normal conglomerate (P65, P61). The conglomerate is shown to be more thermodynamically preferred while the racemic compound is a metastable form in the entire temperature range studied. These two modifications are formed as a mixture during routine crystallization from a solution and characterized by a similar density, however, their structures significantly differ in the parameters of hydrogen bonds. A small difference in the free energies of two phases at room temperature, which is found by differential scanning calorimetry, explains the experimental availability of both forms during crystallization from the solution. The formation of a stronger hydrogen bond in the conglomerate crystals, which is detected by X-ray diffraction and solid-state vibrational spectroscopy, may be explained by a more favorable arrangement of donor and acceptor groups of the neighboring molecules in a homochiral helix of the conglomerate as compared with a heterochiral dimer, which is the main motif in crystals of the racemic compound.



中文翻译:

1-苄基-3-溴-5-羟基-4-[(4-甲基苯基)磺酰基]-1,5-二氢-2Н-吡咯-2-酮非对映异构体的手性依赖性氢键和能量

摘要

得到rac -1-benzyl-3-bromo-5-hydroxy-4-[(4-methylphenyl)sulfanyl]-1,5-dihydro-2 Н -pyrrole-2-one 的两种结晶非对映异构体:复合物 ( P 2 1 / c ) 和普通的砾岩 ( P 6 5 , P 6 1 ))。聚集体显示出在热力学上更受青睐,而外消旋化合物在研究的整个温度范围内都是亚稳定形式。这两种变体在溶液中的常规结晶过程中形成混合物,具有相似的密度,但是,它们的结构在氢键参数上有显着差异。通过差示扫描量热法发现室温下两相自由能的微小差异解释了从溶液结晶过程中两种形式的实验可用性。通过 X 射线衍射和固态振动光谱检测,在聚结晶体中形成更强的氢键,

更新日期:2021-06-18
down
wechat
bug