01528nas a2200217 4500008004100000022001400041245012200055210006900177260000900246300001400255490000700269520076700276100001901043700002301062700001901085700001701104700001601121700002401137700002201161856012701183 2019 eng d a1477-922600aStabilization of bis(chlorogermyliumylidene)s within bifunctional PNNP ligand frameworks and their reactivity studies0 aStabilization of bischlorogermyliumylidenes within bifunctional  cJUN  a7344-73510 v483 a

The diiminodiphosphine (L-im) and diaminodiphosphines (l-NH and l-NMe) with a bifunctional PNNP ligand framework have been employed to host two [GeCl](+) units leading to the formation of bis(chlorogermyliumylidene) 1-3, respectively. The synthetic route involves a 1:2 stoichiometric reaction between the PNNP ligand and GeCl(2)dioxane and the subsequent addition of two equivalents of chloride abstracting agent. Compound 1 is unstable towards coordinating solvents and Lewis bases, resulting in the displacement of the GeCl unit and the formation of rearranged products 4 and 5. However, the diaminodiphosphine coordinated Ge(ii) bis(monocation)s 2 and 3 proved to be stable and revealed their electrophilic behaviour towards the Lewis bases studied.

1 aSahoo, Padmini1 aRaut, Ravindra, K.1 aMaurya, Devesh1 aKumar, Vikas1 aRani, Pooja1 aGonnade, Rajesh, G.1 aMajumdar, Moumita uhttps://library.ncl.res.in/content/stabilization-bischlorogermyliumylidenes-within-bifunctional-pnnp-ligand-frameworks-and02060nas a2200265 4500008004100000022001400041245010900055210006900164260000900233300001400242490000700256520119300263653001701456653001601473653001801489653002501507653001501532100001801547700002301565700001701588700001501605700002001620700002201640856013201662 2021 eng d a1861-472800aIntramolecularly double-donor-stabilized stannylene and its coordination towards Ag(I) and Au(I) centers0 aIntramolecularly doubledonorstabilized stannylene and its coordi cAUG  a2118-21250 v163 aThe intramolecularly double-donor-stabilized stannylene 1 has been synthesized from the salt-metathesis reaction between two equivalents of lithium pyridine ene-amide L1 and SnCl2. Compound 1 exhibits dipolar behavior when reacted with B(C6F5)(3) leading to the zwitterionic compound 2. The reaction of 1 with one equivalent and 0.5 equivalent of AgOTf (OTf=trifluoromethane sulfonate) result in the formation of a stannylene-AgOTf complex 3 and a homoleptic distannylene-silver ionic complex 4, respectively. Analogous to complex 4, the gold(I) complex 5 has been synthesized from the reaction between two equivalents of 1 and 0.5 equivalent of AuCl.SMe2/Me3SiOTf. Complex 5 is the first example of homoleptic stannylene-Au(I) ionic complex among the very scarce reports on stannylene-gold(I) coordination complexes. All compounds have been structurally characterized using single crystal X-ray crystallography. Solution-state characterization have been performed using multinuclear NMR techniques. Detailed DFT calculations on the optimized geometries 1 o, 3 o-5 o reveal the change in sp- hybridization on the pyramidal Sn(II) center upon metal coordination and their bonding overlaps.10acoordination10agold cation10ahybridization10aintramolecular donor10astannylene1 aChibde, Purva1 aRaut, Ravindra, K.1 aKumar, Vikas1 aDeb, Rahul1 aGonnade, Rajesh1 aMajumdar, Moumita uhttps://library.ncl.res.in/content/intramolecularly-double-donor-stabilized-stannylene-and-its-coordination-towards-agi-and-aui01877nas a2200241 4500008004100000022001400041245010600055210006900161260000800230300001600238490000700254520106200261653002301323653002301346653002001369653002201389653001401411100001701425700002401442700002001466700002201486856012701508 2021 eng d a1433-785100aStabilization of the elusive antimony(I) cation and its coordination complexes with transition metals0 aStabilization of the elusive antimonyI cation and its coordinati cNOV a25522-255290 v603 aUpon 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.10aantimony(I) cation10acoordination modes10anucleophilicity10aphosphine ligands10areduction1 aKumar, Vikas1 aGonnade, Rajesh, G.1 aYildiz, Cem, B.1 aMajumdar, Moumita uhttps://library.ncl.res.in/content/stabilization-elusive-antimonyi-cation-and-its-coordination-complexes-transition-metals02021nas a2200193 4500008004100000022001400041245012200055210006900177260000900246300001600255490000700271520131500278100002301593700001701616700002401633700002001657700002201677856012801699 2023 eng d a2041-652000aIntramolecular donor-stabilized tetra-coordinated germanium(iv) di-cations and their Lewis acidic properties0 aIntramolecular donorstabilized tetracoordinated germaniumscivsc  cDEC  a13755-137640 v143 a

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.

1 aPeddi, Balakrishna1 aKhan, Souvik1 aGonnade, Rajesh, G.1 aYildiz, Cem, B.1 aMajumdar, Moumita uhttps://library.ncl.res.in/content/intramolecular-donor-stabilized-tetra-coordinated-germaniumiv-di-cations-and-their-lewis01905nas a2200289 4500008004100000022001400041245004600055210004400101260000900145490000700154520110600161653001801267653001401285653001501299653001701314653001501331100001901346700001801365700002001383700002501403700002401428700001701452700002401469700002101493700002201514856007901536 2023 eng d a1434-194800aZwitterionic tetrastanna(II) cyclic crown0 aZwitterionic tetrastannaII cyclic crown cOCT 0 v263 a

A 12-membered zwitterionic tetrastanna(II) cycle 1 having a crown ether-like topology has been isolated from the deprotonation of 1,1 & PRIME;-methylenediimidazole (B) with two equivalents of Sn[N(SiMe3)(2)](2) (A). The solid-state structure and NMR analysis confirms the tetrastanna(II) cycle 1 to be comprised of two stannate(II) and two stannyliumylidene ion pairs in alternating positions of the heterocycle. Computational analysis shows greater nucleophilicity at the proximally located stannate(II) centers. Nonetheless, the tetrastanna(II) cycle 1 remains poorly reactive due to engagement of Sn-II lone pair electrons in intramolecular donor-acceptor interactions. Simple deprotonation reaction between Sn[N(SiMe3)(2)](2) (A) and N-(diisopropylphenyl)imidazole (C) in equimolar ratio has led to a stannylene 2, involving the formation of a Sn-C covalent bond with the anionic imidazol-2-yl carbon center along with the release of NH(SiMe3)(2). Compound 2 exists as a dimer, where the unsubstituted ring nitrogen atom coordinated intermolecularly to the other stannylene center.

10aDeprotonation10aImidazole10aMacrocycle10aSn-II cation10astannylene1 aSahoo, Padmini1 aChibde, Purva1 aDas, Satyabrata1 aBanerjee, Subhrashis1 aMali, Bhupendra, P.1 aVanka, Kumar1 aGonnade, Rajesh, G.1 aYildiz, Cem., B.1 aMajumdar, Moumita uhttps://library.ncl.res.in/content/zwitterionic-tetrastannaii-cyclic-crown02220nas a2200289 4500008004100000245011500041210006900156260000800225300000900233490000700242520124100249100002501490700002301515700002601538700001701564700002301581700002101604700002901625700002801654700001701682700002101699700002101720700002401741700002001765700002201785856012301807 2026 eng d00aSmallest acyclic tricationic molecule containing a Bis(phosphine)-stabilized low-valent triantimony-based Unit0 aSmallest acyclic tricationic molecule containing a Bisphosphines cMAR a26970 v173 a

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.

1 aMukherjee, Nilanjana1 aPeerless, Benjamin1 aNadurata, Vincent, L.1 aKumar, Vikas1 aSangole, Mayur, P.1 aSingh, Kirandeep1 aWiedemann, Haakon, T. A.1 aKay, Christopher, W. M.1 aKruk, Robert1 aWeigend, Florian1 aDehnen, Stefanie1 aGonnade, Rajesh, G.1 aYildiz, Cem, B.1 aMajumdar, Moumita uhttps://library.ncl.res.in/content/smallest-acyclic-tricationic-molecule-containing-bisphosphine-stabilized-low-valent