Premium
A Dimeric Gallium Hydrazide as an Active Lewis Pair – Complexation and Activation of Me 2 GaH and Various Heterocumulenes
Author(s) -
Uhl Werner,
Willeke Matthias,
Hepp Alexander,
Pleschka Damian,
Layh Marcus
Publication year - 2017
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.201600456
Subject(s) - chemistry , hydrazide , adduct , gallium , lewis acids and bases , stereochemistry , hydride , medicinal chemistry , crystallography , chelation , crystal structure , ligand (biochemistry) , metal , catalysis , inorganic chemistry , organic chemistry , biochemistry , receptor
Treatment of the dimeric gallium hydrazide [Me 2 Ga‐N(2‐Ad)‐NC 5 H 10 ] 2 ( 5 ) with Me 2 GaH resulted in the formation of an adduct 6 by Ga–N bond cleavage and coordination of the metal hydride via a Ga–N and a 3c–2e Ga–H–Ga bond. This reaction reflects the typical behavior of frustrated Lewis pairs. Reactions with heterocumulenes R –N=C= X ( R = Ph, CMe 3 , Dipp, X = O; R = Ph, X = S) or X =C= X ( X = O, S) resulted in the formation of the cyclic Ga–N insertion products Me 2 Ga–N( R )C(O)N(2‐Ad)‐NC 5 H 10 ( 7a – c ), Me 2 GaS 2 C‐N(2‐Ad)‐NC 5 H 10 ( 8 ) or Me 2 Ga X 2 C‐N(2‐Ad)‐NC 5 H 10 [ X = O ( 9 ); S ( 10 )] in moderate to good yields. Three different structural motifs were observed in the solid state: Five‐membered GaNCN 2 heterocycles with exocyclic C=O bonds for compounds 7a – c , four‐membered GaSCN or GaSCS heterocycles for compounds 8 and 9 (chelating coordination of the Ga atoms by SCN and CS 2 ligands) and an eight‐membered (GaOCO) 2 heterocycle for the dimeric CO 2 insertion product 10 . Treatment of 5 with PhCN or Ph 2 CO resulted in a completely different reaction and afforded a dimeric Ga imide 11a or an alcoholate 11b . These reactions may start by retro ‐hydrogallation with the formation of H 10 C 5 N–N=C(C 9 H 14 ) and Me 2 GaH and proceed by addition of the metal hydride to the polar multiple bonds of the nitrile or ketone.