5830-55-7Relevant academic research and scientific papers
Syntheses, spectroscopic characteristics and thermolytic rearrangements of bis-[(trimethylgermyl) methyl]platinum(II) and bis-[(trimethylstannyl) methyl]platinum(II) complexes
Christou, Victor,Young, G. Brent
, p. 157 - 165 (2007/10/03)
The preparations and spectroscopic characteristics are reported of a series of (trimethylgermyl)methyl- and (trimethylstannyl)methyl- platinum(II) complexes with diene and P-donor ancillary ligands, cis-Pt(CH2GeMe3)2L2 (L = PPh3 or PPh2Me; L2 = dppe or cod) and cis-Pt(CH2SnMe3)2L2 (L = PPh3; L2 = cod). Thermolysis of toluene solutions of cis-Pt(CH2GeMe3)2(PPh3)2 leads to cis-Pt(Me)(CH2GeMe2CH2GeMe3)(PPh3)2 via β-alkyl migration, after (non-rate-limiting) phosphine dissociation. Estimated activation parameters (ΔH298 K? = 126 ± 3 kJ mol-1, ΔS? = + 17 ± 7 J mol-1 K-1 and hence ΔG298 K? = 121 ± 5 kJ mol-1) suggest that this system is more migration labile than its silicon analogue, primarily as a result of a lower activation enthalpy. While cis-Pt(CH2GeMe3)2(PPh2Me)2 reacts similarly but less readily, Pt(CH2GeMe3)2(dppe)2 is inert at operable temperatures. Thermolysis of Pt(CH2GeMe3)2(cod) generates 1,1,3,3,-tetramethyldi-1,3-germacyclobutane as the major organogermanium product, while from cis-Pt(CH2SnMe3)2(PPh3)2, 1,1,3,3-tetramethyldi-1,3-stannacyclobutane predominates. Mechanistic implications are discussed.
