College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310032, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Sep;95:230-4. doi: 10.1016/j.saa.2012.05.002. Epub 2012 May 9.
The intermolecular interactions between medroxyprogesterone acetate (MPA) and CHCl(3) and CCl(4) solvent in CHCl(3)/cyclo-C(6)H(12) and CCl(4)/cyclo-C(6)H(12) binary solvent systems have been studied by Fourier transform infrared spectroscopy (FT-IR). The experimental results showed that there are hydrogen bonding interactions between oxygen atoms of all carbonyl groups in MPA and hydrogen atom of CHCl(3) so as to form 1:3 complex of MPA with CHCl(3) and produce three new absorption bands at 1728.9-1736.1, 1712.7-1717.4 and 1661.9-1673.8 cm(-1), respectively. And, 1:1 complex of MPA with CCl(4) is formed in CCl(4)/cyclo-C(6)H(12) binary solvent as a result of hydrogen bonding interaction between C3 carbonyl group and empty d-orbital in chlorine atom of CCl(4) leading to producing new absorption band at 1673.2-1674.2 cm(-1). However, all free carbonyl and associated carbonyl stretching vibrations of MPA in CHCl(3)/cyclo-C(6)H(12) and CCl(4)/cyclo-C(6)H(12) binary solvent systems shift to lower wavenumbers with the increasing of volume fraction of CHCl(3) and CCl(4) in binary solvent systems owing to the dipole-dipole interaction and the dipole-induced dipole interaction between MPA and solvents.
醋酸甲羟孕酮（MPA）与 CHCl（3）和 CCl（4）溶剂在 CHCl（3）/环-C（6）H（12）和 CCl（4）/环-C（6）H（12）二元溶剂系统中的分子间相互作用已通过傅里叶变换红外光谱（FT-IR）进行了研究。实验结果表明，MPA 中所有羰基的氧原子与 CHCl（3）中的氢原子之间存在氢键相互作用，从而形成 MPA 与 CHCl（3）的 1:3 配合物，并在 1728.9-1736.1、1712.7-1717.4 和 1661.9-1673.8 cm（-1）处分别产生三个新的吸收带。并且，由于 CCl（4）中氯原子的空 d 轨道与 C3 羰基之间的氢键相互作用，在 CCl（4）/环-C（6）H（12）二元溶剂中形成 MPA 的 1:1 配合物，导致在 1673.2-1674.2 cm（-1）处产生新的吸收带。然而，由于在二元溶剂系统中 CHCl（3）和 CCl（4）的体积分数增加，MPA 的所有游离羰基和相关的羰基伸缩振动都向较低的波数移动，这是由于 MPA 和溶剂之间的偶极-偶极相互作用和偶极诱导偶极相互作用所致。
