Complexes of hypercoordinate germanium with novel five-membered monoanionic (O,O)-chelating ligands based on 2-hydroxycarboxamides

Hexacoordinate germanium mixed bischelates with the GeCO3Cl2 ligand environment

“…In the same communication 6 a preliminary X-ray study revealed complex 2 as the first structurally characterized example of neutral pentacoordinate germanium complexes containing a 2-hydroxycarboxamide moiety with (O,O)-monoanionic bidentate chelate ligands.…”

“…6 The analogous reaction of trichloro(chloromethyl)germane with N,N-dimethyl-2-(trimethylsilyloxy)acetamide (3) in 1:2 ratio and subsequent treatment with HgCl 2 afforded the bischelate, donor-stabilized cationic complex 4 with pentacoordinated germanium (Scheme 2). 7 …”

“…13 Crystallographic data for 2, 7, and 8 have been deposited at the Cambridge Crystallographic Data Centre. The CCDC numbers are listed in Table 1 (6). Chlorotrimethylsilane (54 g, 0.5 mol) was added dropwise to a solution of 4-methylquinolin-2-one (47.6 g, 0.3 mol) and Et 3 N (50 g, 0.5 mol) in benzene (150 mL).…”

“…Examples are hexacoordinate acetylacetonate 2a,b and benzohydroximate 3 trischelates, a hexacoordinate bischelate with mandelic acid as ligand, 4 and a pentacoordinate bischelate derived from 2-hydroxy-1,2-diphenylethanone. 5 In a recent communication 6 we have reported on the reaction of trichloro(chloromethyl)germane with racemic N,N-dimethyl-2-(trimethylsilyloxy)-2-phenylacetamide (1) yielding 2-[dichloro(chloromethyl)germyloxy]-N,N-dimethyl-2-phenylacetamide (2, Scheme 1), followed by the transformation of the monochelate 2 into a complex with two (O→Ge)-chelating ligands of different types (see below, Scheme 3, a). …”

O,O-Monochelate complexes of silicon and germanium halides: The derivatives of l-mandelic N,N-dimethylamide

“…The complexes of these elements with (C,O [6,7] and also by the derivatives of 2-hydroxypyridine N-oxide and acylamides [8] (see also [4c,9] and the citations therein). The synthesis, structure and chemical transformations of another (O,O)-monochelate of pentacoordinate germanium, [1-(dimethylcarbamoyl)-1-phenylmethoxy]dichloro(chloromethyl)germane, were reported by us in a preliminary communication [10]. The latter complex was prepared from chloromethyltrichlorogermane and racemic N,N-dimethyl-Otrimethylsilylmandelic amide [10].…”