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From Gallium Hydride Halides to Molecular Gallium Sulfides
Author(s) -
Schmidbaur Hubert,
Nogai Stefan D.
Publication year - 2004
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.200400203
Subject(s) - chemistry , gallium , hydride , adduct , pyridine , sulfide , medicinal chemistry , diethyl ether , acetonitrile , inorganic chemistry , polymer chemistry , crystallography , metal , organic chemistry
Complexes of the type (L)GaHCl 2 , with L = tertiary phosphines or pyridines, have been prepared from (HGaCl 2 ) 2 and the ligands in diethyl ether. The products are stable crystalline solids soluble in common organic solvents. The presence of the Ga‐H function has been confirmed by IR and NMR spectroscopy and by single crystal X‐ray diffraction, carried out for the 1:1 adducts with L = PCy 3 and PPh 3 (two polymorphs) and for the 2:1 adduct with L = (CH 2 PPh 2 ) 2 (dppe, two different solvates). The reaction of PVi 3 with (HGaCl 2 ) 2 gives an insoluble polymer owing to the hydrogallation of vinyl groups by the gallium hydride units (no Ga‐H functions are left in the product).Treatment of the complexes (R 3 P)GaHCl 2 with H 2 S, metal sulfides or (Me 3 Si) 2 S gave only insoluble, ill‐defined products.‐ The 1:1 adduct (L′)GaHCl 2 , with L′ = 4‐dimethylamino‐pyridine, reacts with (Me 3 Si) 2 S in acetonitrile at ambient temperature to give an only partially sulfur‐substituted product of the net formula (L′)GaSH 0.66 Cl 0.34 . With excess ligand L′, under reflux conditions and after longer reaction times, a pyridine complex of the tetranuclear, molecular gallium sulfide Ga 4 S 6 is obtained in low yield. The core of the compound with the composition (L′) 4 Ga 4 S 6 has an adamantane structure resembling a cluster unit of the binary gallium sulfide polymorphs Ga 2 S 3 . The edge‐sharing Ga 3 S 3 six‐membered rings are all in a chair conformation as found previously for the pyridine complexes of the ternary compounds [(L)GaEX] 3 (with E = S, Se and X = Cl, Br) and for the bicyclic dication [(L) 6 Ga 4 S 5 ] 2+ . Thermolysis and degradation under mass spectrometry conditions lead to sublimation of L′ and leave amorphous Ga 2 S 3 . The reaction of (L′)GaCl 3 with (Me 3 Si) 2 S did not afford any molecular gallium sulfide complex. A comparison of the structural data for (L′)GaCl 3 and (L′) 4 Ga 4 S 6 suggests a much poorer acceptor character of the gallium sulfide cluster.