z-logo
Premium
Multiple Isomers of a Small, Strained Phosphaphane
Author(s) -
Xiao Yonglong,
Mague Joel T.,
Pascal Robert A.
Publication year - 2018
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201801106
Subject(s) - chemistry , phosphine , lone pair , tris , coupling constant , crystallography , stereochemistry , spin (aerodynamics) , cis–trans isomerism , molecule , organic chemistry , catalysis , biochemistry , physics , particle physics , engineering , aerospace engineering
Three cyclophanes with the formula (C 28 H 31 PS 3 ) n , where n = 1 or 2, were isolated from the base‐promoted macrocyclization of tris(2‐mercaptophenyl)phosphine ( 4 ) and tris(3‐bromopropyl)methane ( 5 ). Spectroscopic and X‐ray analysis showed them to be the in,in ‐isomer 1 , the in,out ‐isomer 2 , and a dimeric in,out,in,out ‐isomer 3 . Compounds 1 and 3 display approximately C 3 ‐symmetric and C i ‐symmetric structures, respectively, in the crystal, but compound 2 adopts two distinct low‐symmetry conformations in the solid state. In each case, the observed structures correspond to the lowest energy conformations of their respective isomers as calculated at the B3PW91/6‐31G(d) level of theory. The in,in ‐isomer 1 displays a close contact between the phosphine in ‐lone pair and the in ‐methine group, with through‐space spin–spin coupling constants of J PH = 9 Hz and J PC = 24 Hz, the latter of which appears to be the largest reported phosphorus‐carbon through‐space coupling constant.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here