01527nas a2200217 4500008004100000022001400041245012200055210006900177260000900246300001400255490000700269520076700276100001901043700002301062700001901085700001701104700001601121700002401137700002201161856012601183 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 uhttp://library.ncl.res.in/content/stabilization-bischlorogermyliumylidenes-within-bifunctional-pnnp-ligand-frameworks-and02059nas a2200265 4500008004100000022001400041245010900055210006900164260000900233300001400242490000700256520119300263653001701456653001601473653001801489653002501507653001501532100001801547700002301565700001701588700001501605700002001620700002201640856013101662 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 uhttp://library.ncl.res.in/content/intramolecularly-double-donor-stabilized-stannylene-and-its-coordination-towards-agi-and-aui01876nas a2200241 4500008004100000022001400041245010600055210006900161260000800230300001600238490000700254520106200261653002301323653002301346653002001369653002201389653001401411100001701425700002401442700002001466700002201486856012601508 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 uhttp://library.ncl.res.in/content/stabilization-elusive-antimonyi-cation-and-its-coordination-complexes-transition-metals02020nas a2200193 4500008004100000022001400041245012200055210006900177260000900246300001600255490000700271520131500278100002301593700001701616700002401633700002001657700002201677856012701699 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 uhttp://library.ncl.res.in/content/intramolecular-donor-stabilized-tetra-coordinated-germaniumiv-di-cations-and-their-lewis01904nas a2200289 4500008004100000022001400041245004600055210004400101260000900145490000700154520110600161653001801267653001401285653001501299653001701314653001501331100001901346700001801365700002001383700002501403700002401428700001701452700002401469700002101493700002201514856007801536 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 uhttp://library.ncl.res.in/content/zwitterionic-tetrastannaii-cyclic-crown