@article {46716, title = {Amidinato germylene-zinc complexes: synthesis, bonding, and reactivity}, journal = {Chemistry-An Asian Journal}, volume = {15}, year = {2020}, month = {OCT }, pages = {3116-3121}, type = {Article}, abstract = {

Despite the explosive growth of germylene compounds as ligands in transition metal complexes, there is a modicum of precedence for the germylene zinc complexes. In this work, the synthesis and characterization of new germylene zinc complexes [PhC(NtBu)(2)Ge{N(SiMe3)(2)}-\> ZnX2](2)(X= Br (2) and I (3)) supported by (benz)-amidinato germylene ligands are reported. The solid-state structures of2and3have been validated by single-crystal X-ray diffraction studies, which revealed the dimeric nature of the complexes, with distorted tetrahedral geometries around the Ge and Zn center. DFT calculations reveal that the Ge-Zn bonds in2and3are dative in nature. The reaction of2with elemental sulfur resulted in the first structurally characterized germathione stabilized ZnBr(2)complexes PhC(NtBu)(2)Ge(=S){N(SiMe3)(2)}-\> ZnBr2(5). Therefore, the Ge=S in5is in-between Ge-S single and Ge=S double bond length, owing to the coordination of a sulfur lone pair of electrons to ZnBr2.

}, keywords = {DFT, Germathione, Germylene, X-ray Structure, zinc}, issn = {1861-4728}, doi = {10.1002/asia.202000807, Early Access Date = SEP 2020}, author = {Yadav, Sandeep and Kumar, Rohit and Raj, K. Vipin and Yadav, Prashant and Vanka, Kumar and Sen, Sakya S.} } @article {46956, title = {Tale of biphenyl and terphenyl substituents for structurally diverse ketiminato magnesium, calcium and germanium complexes}, journal = {Chemistry-An Asian Journal}, volume = {15}, year = {2020}, month = {MAR}, pages = {820-827}, type = {Article}, abstract = {

In this paper, we have used two N,O-ketiminato ligands (L1 and L2) with biphenyl and terphenyl substituent on the nitrogen atom. Deprotonation of L1 with KN(SiMe3)(2) and subsequent reaction with MgI2 led to a homoleptic dinuclear magnesium complex (1) with a Mg2O2 four-membered ring. Deprotonation with nBuLi and subsequent reaction with MgI2 afforded a unusual dinuclear magnesium complex (2) with a Mg2O2 ring. Extension of the ligand for calcium resulted in a trinuclear calcium complex (3) with six four-membered Ca2O2 rings. We could not isolate any chelating complex when L2 was used as a ligand, and only oxygen bound magnesium (4) and calcium (5) adducts were isolated. DFT studies were performed to understand this dissimilar behavior. More diverse results were obtained when lithiated L1 and L2 were treated with germanium dichloride. We were able to stabilize a monomeric germylene monochloride (7) with L1. However, with L2, an unusual ligand scrambling, and a C-C coupling take place, leading to the formation of a secondary carbocation with GeCl3- as a counter-anion (8). Besides, a germanium dichloride adduct (9) bound to the oxygen center of the ligand was obtained as the minor product.

}, keywords = {calcium, Germylene, ligand, Magnesium, X-ray Structure}, issn = {1861-4728}, doi = {10.1002/asia.201901801, Early Access Date = FEB 2020}, author = {Kumar, Rohit and Yadav, Sandeep and Gour, Kritika and Sangtani, Ekta and Ranjan Dash, Soumya and Raja, Abhishekram and Vanka, Kumar and Gonnade, Rajesh G. 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 {49616, title = {Germylene mediated reductive C-C and C-N coupling of an isocyanide and its device application}, journal = {Angewandte Chemie-International Edition}, volume = {64}, year = {2025}, month = {FEB }, type = {Article}, abstract = {

We have demonstrated a unique reductive coupling of 4-iodophenyl isocyanide, facilitated by a perimidine-based N-heterocyclic germylene (NHGe), which yields a bis-spirogerma compound featuring simultaneous C-C and C-N bond formation. This reaction, which leads to the oxidation of germanium from +2 to +4, represents a significant departure from previously documented isocyanide-germylene interactions. The product exhibits extensive conjugation across its bicyclic C4Ge2N2 framework, conferring distinct photophysical properties, including prominent orange luminescence in both solution and solid states. The photophysical properties are supported by the TD-DFT calculations confirming an n -\>pi* transition. The potential application of this compound in optoelectronic devices, particularly as a hole transport layer in PbS quantum dot solar cells, is also explored, with promising preliminary results.

}, keywords = {Germylene, hole transport layer, Isocyanide, reductive coupling}, doi = {10.1002/anie.202417052}, author = {Gour, Kritika and Pramanik, Debjit and Dash, Soumya Ranjan and Shinde, Dipak Dattatray and Venugopal, Geethu and Vanka, Kumar and Rath, Arup K. and Sen, Sakya S.} }