@article {47714,
	title = {Stabilization of the elusive antimony(I) cation and its coordination complexes with transition metals},
	journal = {Angewandte Chemie-International Edition},
	volume = {60},
	year = {2021},
	month = {NOV},
	pages = {25522-25529},
	type = {Article},
	abstract = {Upon stabilization by 5,6-bis(diisopropylphosphino)acenaphthene to form compound 1, the fugitive antimony (I) cation exhibited nucleophilic behavior towards coinage metals. Compound 1 was strategically synthesized at room temperature from SbCl3, the bis(phosphine), and trimethylsilyl trifluoromethanesulfonate taken in a 1:2:3 ratio, whereby the bis(phosphine) plays the dual role of a reductant and a supporting ligand. The generation of 1 involves two-electron oxidation of the ligand to form a P-P bonded diphosphonium dication. Compound 1 was separated from this dication to give both products in pure form in moderate yields. Despite the overall positive charge, the Sb-I site in 1 was found to bind to metal centers, forming complexes with Au-I, Ag-I and Cu-I. Compound 1 reduced Cu-II to Cu-I and formed a coordination complex with the resulting Cu-I species. The effects of the electron-rich bis(phosphine) and the constrained peri geometry in stabilizing and enhancing the nucleophilicity of 1 have been rationalized through computational studies.},
	keywords = {antimony(I) cation, coordination modes, nucleophilicity, phosphine ligands, reduction},
	issn = {1433-7851},
	doi = {10.1002/anie.202111339},
	author = {Kumar, Vikas and Gonnade, Rajesh G. and Yildiz, Cem B. and Majumdar, Moumita}
}
@article {48969,
	title = {Intramolecular donor-stabilized tetra-coordinated germanium(<sc>iv</sc>) di-cations and their Lewis acidic properties},
	journal = {Chemical Science },
	volume = {14},
	year = {2023},
	month = {DEC },
	pages = {13755-13764},
	type = {Article},
	abstract = {<p>
	We report the first examples of intramolecular phosphine-stabilized tetra-coordinated germanium(iv) di-cationic compounds: [(L2Ge)-Ge-iPr][CF3SO3](2)3iPr and [(L2Ge)-Ge-Ph][CF3SO3](2)3Ph (L-iPr = 6-(diisopropylphosphanyl)-1,2-dihydroacenaphthylene-5-ide; L-Ph = 6-(diphenylphosphanyl)-1,2-dihydroacenaphthylene-5-ide). The step wise synthetic strategy involves the isolation of neutral and mono-cationic Ge(iv) precursors: [(L2GeCl)-Ge-iPr][X] (X = GeCl(3)1iPr, OTf 2iPr), [(L2GeCl2)-Ge-Ph] 1Ph and [(L2GeCl)-Ge-Ph][OTf] 2Ph. Both 3iPr and 3Ph exhibit constrained spiro-geometry. DFT studies reveal the dispersion of di-cationic charges over P-Ge-P sites. Anion or Lewis base binding occurs at the Ge site resulting in relaxed distorted trigonal bipyramidal/tetrahedral geometry. 3iPr and 3Ph activate the Si-H bond initially at the P-site. The hydride ultimately migrates to the Ge-site rapidly giving [(L2GeH)-Ge-Ph][CF3SO3] 3PhH, while sluggishly forming [(L2GeH)-Ge-iPr][CF3SO3] 3iPrH. Compounds 3iPr and 3Ph were tested as catalysts for the hydrosilylation of aromatic aldehydes. While catalytic hydrosilylation proceeded via the initial Et3Si-H bond activation in the case of 3iPr, compound 3Ph as a catalyst showed a masked Frustrated Lewis Pair (FLP) type reactivity in the catalytic cycle.</p>
},
	issn = {2041-6520},
	doi = {10.1039/d3sc03717g},
	author = {Peddi, Balakrishna and Khan, Souvik and Gonnade, Rajesh G. and Yildiz, Cem B. and Majumdar, Moumita}
}
@article {50085,
	title = {Smallest acyclic tricationic molecule containing a Bis(phosphine)-stabilized low-valent triantimony-based Unit},
	journal = {Nature Communications},
	volume = {17},
	year = {2026},
	month = {MAR},
	pages = {2697},
	type = {Article},
	abstract = {<p>
	Element-element bonded multiply charged cationic species are well known as dimers or small cyclic oligomers in the condensed phase. However, the smallest acyclic version, a trinuclear unit possessing greater than a monocationic charge, has remained elusive. Here we introduce a bis(phosphine) supported low valent triantimony-based tricationic compound as a new entrant in this field. Structural elucidation and electronic understanding reveal a W-shaped tricationic unit comprising of a three-center four-electron sigma-bonded triantimony moiety that is terminally capped by bis(phosphine) ligands, with the central antimony atom having two lone pairs of electrons. The unique counter trianion [Sb(O)2(OTf)4]3- (OTf = CF3SO3) possesses reactive polar Sb delta+-O delta- bonds, the structure of which is determined from single crystal X-ray diffraction analysis. The ensemble of reactive molecular fragments found in this highly charged antimony-based compound makes it thermally unstable. Nonetheless, this fully characterized fleeting species shows a diverse reactivity profile, advancing the isolation of various novel antimony compounds, including the formation of a distinct low-valent antimony-cobalt carbonyl cluster.</p>
},
	doi = {10.1038/s41467-026-70910-5},
	author = {Mukherjee, Nilanjana and Peerless, Benjamin and Nadurata, Vincent L. and Kumar, Vikas and Sangole, Mayur P. and Singh, Kirandeep and Wiedemann, Haakon T. A. and Kay, Christopher W. M. and Kruk, Robert and Weigend, Florian and Dehnen, Stefanie and Gonnade, Rajesh G. and Yildiz, Cem B. and Majumdar, Moumita}
}
