1,2‐Dithiooxalato‐Bridged Heterobimetallic Complexes as Single‐Source Precursors for Ternary Metal Sulfide Semiconductors

The new 1,2‐dithiooxalato‐bridged bimetallic Cu–Ga, Cu–In, and Cu–Sn complexes [{(Ph 3 P) 2 Cu(μ‐S 2 C 2 O 2 )} 3 Ga] ( 1 ), [{(Ph 3 P) 2 Cu(μ‐S 2 C 2 O 2 )} 3 In] ( 2 ), [(Ph 3 P) 2 Cu(μ‐S 2 C 2 O 2 )In(S 2 CNEt 2 ) 2 ] ( 3 ), and [{(Ph 3 P) 2 Cu(μ‐S 2 C 2 O 2 )} 2 Sn(S 2 C 2 O 2 )] ( 4 ) were prepared and spectroscopically fully characterized. The crystal structures of 2 – 4 are presented. Complexes 3 and 4 are potential molecular single‐source precursors (SSP) for the ternary semiconductors CuInS 2 and Cu 2 SnS 3 , respectively, which can be manipulated under ambient conditions. Indeed, a study of the thermal degradation of 3 and 4 revealed that 3 affords pure nanoscaled CuInS 2 (mean diameter ca. 2 nm) when the decomposition is carried out in an oleylamine solution by using a hot‐injection or arrested‐precipitation technique at temperatures well below 250 °C. In contrast, 4 decomposes under the same reaction conditions in an ambiguous manner and forms mixed binary chalcogenide phases. This can be explained by a subtle influence of the relative stability of possible Sn II and Sn IV intermediates in the case of SSP [{(Ph 3 P) 2 Cu(μ‐S 2 C 2 O 2 )} 2 Sn(S 2 C 2 O 2 )] ( 4 ).