The molecular structures of gaseous tetrafluorohydridophosphorane, HPF4, and trifluorodihydridophosphorane, H2PF3, as determined by electron diffraction
作者:Anthony J. Downs、G. Sean McGrady、Elizabeth A. Barnfield、David W. H. Rankin
DOI:10.1039/dt9890000545
日期:——
gaseous tetrafluorohydridophosphorane, HPF4, and trifluorodihydridophosphorane, H2PF3, have been determined by electron diffraction. The results indicate that both molecules adopt structures based on a trigonal bipyramid centred on the phosphorus atom, with the hydrogen atoms occupying equatorial sites, in conformity with C2v symmetry. Salient structural parameters (ra) are: (i) for HPF4, r(P–Feq) 153
气态四氟氢化磷环烷HPF 4和三氟二氢化磷环烷H 2 PF 3的结构已经通过电子衍射确定。结果表明,两个分子均采用以磷原子为中心的三角双锥体结构,氢原子占据赤道位点,符合C 2 v对称性。突出的结构参数(r a)为:(i)HPF 4,r(P–F eq)153.7(0.4),r(P–F ax)159.1(O.4)和r(P–H)132.4 (4.6)下午;H–P–F当量123.0(0.9)和H-P-F斧87.8(0.2)°; ( ii)对于H 2 PF 3, r(P-F aq)154.4(0.4), r(P-F ax)161.3(0.2)和r(P-H)132.2(1.1)pm;H–P–F eq 119.6(4.4)和F eq –P–F ax 91.7(0.2)°。因此,氢置换氟会导致异常的P–H键变短,顶部P–F键衰减以及PF n片段变形( n = 4或3),从而导致顶部P–F键朝着弯曲,而HPF