@article {49393, title = {Activation of carbon disulfide by a hypersilyl germylene}, journal = {Dalton Transactions}, volume = {53}, year = {2024}, month = {JUL}, type = {Article}, abstract = {

In this work, the insertion of CS2 into the Ge-Si bond of PhC(NtBu)2Ge-Si(SiMe3)3 (1) has been investigated, resulting in the formation of PhC(NtBu)2Ge-C( 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 S)-S-Si(SiMe3)3 (2). Interestingly, the addition of NHC to 2 allows the release of NHCCS2 with concomitant regeneration of 1. Addition of another equivalent of 1 or an analogous hypersilyl silylene, [PhC(NtBu)2Si-Si(SiMe3)3], to 2 led to the formation of compounds with a GeS (3) or a SiS (4) bond. In this work, the insertion of CS2 into the Ge-Si bond of PhC(NtBu)2Ge-Si(SiMe3)3 (1) has been investigated, resulting in the formation of PhC(NtBu)2Ge-C(S)-S-Si(SiMe3)3 (2).

}, issn = {1477-9226}, doi = {10.1039/d4dt01573h}, author = {Ajithkumar, V. S. and Khilari, Nripen and Ghanwat, Pratiksha B. and Venugopal, Geethu and Koley, Debasis and Sen, Sakya S.} } @article {49897, title = {C=C insertion over N=C=O of allyl isocyanate into the Ge-Si bond of a germylene}, journal = {European Journal of Inorganic Chemistry}, volume = {28}, year = {2025}, month = {SEP}, type = {Article}, abstract = {

Two isocyanates are reacted with the germylene, PhC(NtBu)(2)Ge-Si(SiMe3)(3) (1). Phenyl isocyanate undergoes catalytic cyclotrimerization with 1 leading to 1,3,5-triphenyl isocyanurate (2), while allyl isocyanate undergoes both cyclotrimerization and the C=C bond insertion between the Ge-Si bond. The constitution of 3 is determined by single-crystal X-ray studies. The contrasting reactivity pattern is explained by comprehensive density functional theory studies.

}, keywords = {Cyclotrimerization, Density functional theory, Germylene, Insertion, isocyanates}, issn = {1434-1948}, doi = {10.1002/ejic.202500305}, author = {Ajithkumar, V. S. and Khilari, Nripen and Ghanwat, Pratiksha B. and Koley, Debasis and Sen, Sakya S.} } @article {50095, title = {Magnesium-catalyzed CO2 reduction to formic acid or methanol: solvent or no solvent settles the selectivity}, journal = {Inorganic Chemistry}, volume = {65}, year = {2026}, month = {APR }, pages = {8793-8803}, type = {Article}, abstract = {

Reducing the carbonyl (C=O) group in carbon dioxide is a difficult yet crucial step for producing valuable chemical compounds. This approach holds promise for creating new methods to utilize nonfossil-based raw materials. Using catalysts made from abundant, inexpensive, and environmentally friendly metals, such as magnesium, could significantly advance the development of sustainable synthetic techniques. In this study, a magnesium pincer compound (1) is shown to facilitate the reduction of CO2 with pinacolborane as the reductant. When used without a solvent, the reaction produces methoxyborane, whereas in THF, it leads to formoxyborane. Formoxyborane has been identified as a {\textquoteleft}{\textquoteleft}missing link{\textquoteright}{\textquoteright} in homogeneous CO2 reduction by catalysts based on alkaline earth metal elements. The variation in product selectivity was substantiated through DFT calculations. The initial generation of the Mg(II) hydride catalyst both in the absence and presence of THF entails an activation barrier within 25-26 kcal mol-1. However, the rate-determining step, in the absence of a solvent, involves hydride transfer-mediated reduction at the formate fragment accompanying a transition barrier of 27.3 kcal mol-1. In the presence of THF, the rate-determining step involves hydride transfer to the Mg center with a barrier of 29.2 kcal mol-1, generating the catalyst and boryl formate.

}, issn = {0020-1669}, doi = {10.1021/acs.inorgchem.6c01255}, author = {Mahata, Biplab and Khilari, Nripen and Koley, Debasis and Sen, Sakya S.} }