Pelloni S, Provasi P F, Pagola G I, Ferraro M B, Lazzeretti P
Polo agroindustriale di Parma c/o I.T.I.S. Galileo Galilei , Via Martiri di Cefalonia 14, S. Secondo, 43126 Parma, Italy.
Departamento de Fı́sica, Northeastern University , Av. Libertad 5500, W3400 AAS Corrientes, Argentina.
J Phys Chem A. 2017 Dec 7;121(48):9369-9376. doi: 10.1021/acs.jpca.7b09104. Epub 2017 Nov 21.
The trace of tensors that account for chiroptical response of the HO molecule is a function of the HO-OH dihedral angle. It vanishes at 0° and 180°, due to the presence of molecular symmetry planes, but also for values in the range 90-100° of this angle, in which the molecule is unquestionably chiral. Such an atypical effect is caused by counterbalancing contributions of diagonal tensor components with nearly maximal magnitude but opposite sign, determined by electron flow in open or closed helical paths, and associated with induced electric and magnetic dipole moments and anapole moments. For values of dihedral angle external to the 90-100° interval, the helical paths become smaller in size, thus reducing the amount of cancellation among diagonal components. Shrinking of helical paths determines the appearance of extremum values of tensor traces approximately at 50° and 140° dihedral angles.
描述HO分子手性光响应的张量迹是HO-OH二面角的函数。由于分子对称面的存在，它在0°和180°时为零，但在该角度90 - 100°范围内的值时也为零，而在此角度范围内分子无疑是手性的。这种非典型效应是由对角张量分量几乎具有最大幅度但符号相反的相互抵消作用引起的，这由开放或闭合螺旋路径中的电子流决定，并与感应电偶极矩、磁偶极矩和电四极矩相关。对于二面角在90 - 100°区间之外的值，螺旋路径尺寸变小，从而减少对角分量之间的抵消量。螺旋路径的收缩决定了张量迹在大约50°和140°二面角处出现极值。
