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Donor‐unsupported Phosphanylmethanides Li[CH 2 P R 2 ] ( R = t Bu, Ph) – Crystal Structure of Li[CH 2 P t Bu 2 ] Solved by XRPD and DFT‐D Calculations
Author(s) -
Fink Lothar,
Samigullin Kamil,
Bodach Alexander,
Alig Edith,
Wagner Matthias,
Lerner HansWolfram
Publication year - 2016
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201500811
Subject(s) - monoclinic crystal system , crystallography , crystal structure , chemistry , castep , methyllithium , deprotonation , ring (chemistry) , stereochemistry , center (category theory) , density functional theory , computational chemistry , ion , organic chemistry
The solvent‐free methyllithium derivatives Li[CH 2 P R 2 ] ( R = t Bu, Ph) were prepared via the reaction of CH 3 P R 2 with Li[ t Bu]. It should be noted that the deprotonation of CH 3 P t Bu 2 with Li[ t Bu] occurred at 60 °C, whereas Li[CH 2 PPh 2 ] was already formed from CH 3 PPh 2 with Li[ t Bu] at ambient temperature. The structure determination of di‐ tert ‐butylphosphanylmethyllithium was performed by high resolution X‐ray powder diffraction analysis at different temperatures. This led to two possible structure solutions with similar quality criteria (space groups Iba 2 and I 2/ a ). Therefore CASTEP DFT‐D calculations were applied to verify the correct crystal structure. The solid‐state structure of di‐ tert ‐butylphosphanylmethyllithium consists of alternating edge‐sharing six‐ and four‐membered rings, which form a polymeric, infinite double‐chain along the crystallographic c axis in the monoclinic space group I 2/ a . Two Li[CH 2 P t Bu 2 ] units connected via an inversion center form a six‐membered Li 2 C 2 P 2 ring in the chair conformation. The nearly flat four‐membered Li 2 C 2 ring, is oriented perpendicularly to the twofold axis.