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The 1 : 2 reaction of the imidazole‐based dithiolate (2) with GeCl₂ • dioxane in THF/TMEDA gives3, a TMEDA‐complexed dithiolene‐based germylene. Compound3is converted to monothiolate‐complexed (5) and N‐heterocyclic carbene‐complexed (7) germanium(II) dithiolene complexes via Lewis base ligand exchange. A bis‐dithiolene‐based germylene (8), involving a 3c–4e S‐Ge‐S bond, has also been synthesized through controlled hydrolysis of7. The bonding nature of3,5, and8was investigated by both experimental and theoretical methods.

 

While the 1 : 1 reaction of 3 with an N-heterocyclic carbene ({(Me)CN(i-Pr)} 2 C:) in THF resulted in ligand-substituted product 4, the corresponding 1 : 2 reaction (in the presence of H 2 O) gives the first structurally characterized germanium tris(dithiolene)dianion 5 as the major product and the “naked” dithiolene radical 6˙ as a minor by-product. The structure and bonding of 4 and 5 were probed by experimental and theoretical methods. Our study suggests that carbene-mediated partial hydrolysis may represent a new method to access tris(dithiolene) complexes of main-group elements. 

The discovery of another monoclinic polymorph in the niobium trisulfide system expands the structural possibilities for quasi-1D transition metal trichalcogenide materials. We describe here NbS₃-VI prepared by chemical vapor transport (CVT) using ammonium chloride as the transport agent rather than the typical iodine or excess chalcogen. This example establishes precedent for transport agent control over CVT product polymorphism, thereby opening an alternative avenue for structural engineering. The single crystal x-ray diffraction structure of NbS₃-VI shows that this polymorph unexpectedly incorporates features of both NbS₃-IV and NbS₃-V; specifically, NbS₃-VI contains corrugated chains with paired Nb–Nb and uniform chains with unpaired, equidistant Nb centers. We also use single crystal x-ray diffraction to compare NbS₃-VI with (Nb_0.6Ti_0.4)S₃, which contains solely uniform chains with slightly shorter metal–metal distances than those of uniform NbS₃-VI chains.