Stabilisation of an inorganic digallane by the phosphinobisthiolato P,S,S pincer ligand PPh(2-SC6H4)2

Abstract

The pincer ligand PPh(2-HSC 6 H 4 ) 2 reacts with GaCl 3 in the presence of triethylamine to yield the anionic gallium complex 4)] were obtained by reaction of PPh(2-HSC 6 H 4 ) 2 with trialkyl gallium compounds (GaMe 3 , Ga t Bu 3 ). Compound 4 is light-sensitive and decomposes in daylight or under UV irradiation. Three decomposition products could be isolated: tetranuclear hydrido-bridged mixed-valent gallium(II)-gallium(III) complex [Ga III {PPh(2-SC 6 H 4 )-k 2 S,P-m-(2-SC 6 H 4 )-kS 0 } 2 ] 2 (m 3 -H) 2 Ga II 2 (Ga-Ga) (5), gallium(II) complex [Ga{PPh(2-SC 6 H 4 ) 2 -k 3 S,S 0 ,P}] 2 (Ga-Ga) (6), and sulfido-bridged dinuclear complex [Ga{PPh(2-SC 6 H 4 ) 2 -k 3 S,S 0 ,P}] 2 (m-S) (7). The molecular structures of 2-7 are described.

Coordination chemistry of the main group elements with phosphine, arsine and stibine ligands

“…However, for gallium, reduction of syn-[GaCl(P 2 N 2 )] with KC 8 produces the dimer [{Ga(P 2 N 2 )} 2 ], which has an unsupported Ga-Ga bond [168,169]. A variety of coordination modes are present in the gallium(III) complexes of o-C 6 H 4 PPh 2 (SH), o-C 6 H 4 AsPh 2 (SH) and PhP(o-C 6 H 4 SH) 2 , with the majority containing deprotonated thiolates [218,219].…”

Variable Coordination Modes of Potentially Tetradentate Phosphino‐ and Arsinoarylthiolato Ligands Derived from E(2‐SHC6H4)3 (E = P, As) in Gallium(III) Complexes

“…The gallium–sulfur bond lengths [2.3030(5) and 2.3119(5) Å] are in the range of those reported for [PPh 4 ][Ga{PhP(2‐SC 6 H 4 ) 2 ‐κ 3 S , S′,P }{PhP(2‐SC 6 H 4 ) 2 ‐κ 2 S , S′ }] [2.2970(9)–2.392(1) Å]4 and slightly longer than those observed in anionic gallium thiolates, e.g., [NEt 3 H][Ga{SC(O)Ph‐κ S } 4 ] · H 2 O [2.270(2)–2.287(10)],12 [NEt 4 ][Ga(SPh) 4 ] [2.242(3)–2.260(3) Å], [NPr 4 ][Ga(SEt) 4 ] [2.264(1) Å],13 [NEt 4 ] 2 [Ga(μ‐S)(SPh) 2 ] 2 [2.264–2.288 Å]13 and [NH 2 i Pr 2 ][Ga(S i Pr) 4 ] [2.2541(6)–2.2796(6) Å] 14. The Ga–C bond length of 1.944(2) Å is in the same range as those of previously reported related gallium alkyl complexes of PSH and PS 2 H 2 3,4 and other Ga–C methyl bonds 15. The Ga–P bond length [2.3327(5) Å] is comparable to those found in adducts, e.g., GaCl 3 (PMe 3 ) [2.353(2) Å],16 GaCl 3 {P(SiMe 3 ) 3 } [2.379(5) Å],17 or in related complexes such as GaMe{PhP(2‐SC 6 H 4 ) 2 ‐κ 3 S , S′,P } [2.3491(4) Å]4 and Ga t Bu{PhP(2‐SC 6 H 4 ) 2 ‐κ 3 S , S′,P } [2.3602(8) Å] 4.…”

“…Polydentate heterodonor ligands, which combine phosphorus or arsenic with the multiple coordination patterns of sulfur (P, S and As, S ligands) have been shown to be highly versatile ligands that form stable complexes with a wide range of main group and transition metals 1,2. Due to their wide range of coordination modes, bi‐, tri‐ and tetradentate phosphino‐ and arsinoarylthiols, e.g., E Ph 2 ‐2‐SHC 6 H 4 ( ESH ), E Ph(2‐SHC 6 H 4 ) 2 ( ES 2 H 2 ) and E (2‐SHC 6 H 4 ) 3 ( ES 3 H 3 ) ( E = P, As), have been employed in main group3–5 and transition metal complexes6 with potential applications in catalysis,2,6,7 materials science,8 and medicinal chemistry 9,10…”

“…As the coordination modes of bidentate ES – and tridentate ES 2 2 – ligands toward gallium(III) were shown to vary depending on E (P or As),3,4 we have extended these studies to potentially tetradentate phosphino‐ and arsinoarylthiolato ligands derived from E (2‐SHC 6 H 4 ) 3 ( E = P, As) and now report their reaction with GaMe 3 , yielding the organogallium complexes GaMe{P(2‐SC 6 H 4 ) 2 (2‐SHC 6 H 4 )‐κ 3 S , S′,P } ( 1 ), [NEt 3 H][GaMe{P(2‐SC 6 H 4 ) 3 ‐κ 3 S , S′,P }] ( 2 ), and GaMe{ E (2‐SC 6 H 4 ) 2 (2‐S{GaMe 2 (THF)}C 6 H 4 )‐κ 3 S , S′,E } [ E = P ( 3 ), As ( 4 )]. Serendipitous hydrolysis of 4 gave small amounts of the hexanuclear gallium hydroxide complex cyclo ‐{GaMe(μ‐OH)} 6 {As(2‐SC 6 H 4 ) 3 ‐κ S , S′,S′′ } 2 ( 5 ).…”

Cytotoxicity, apoptosis and study of the DNA-binding properties of bi- and tetranuclear gallium(III) complexes with heterocyclic thiolato ligands

“…Thus, as a continuation of our research on gallium complexes [38][39][40][41], we here present the synthesis, characterization and anticancer studies of gallium(III) thiolato complexes containing the heterocyclic derivatives 2-mercapto-1-methylimidazole (SH-imi), 5-mercapto-1-methyltetrazole (SH-tet), 2-mercaptobenzothiazole (SHben) and 5-phenyl-1,3,4-oxadiazole-2-thiol (SH-oxa).…”