Intramolecularly coordinated organotin tellurides: stable or unstable?

Controlling Catenation in Germanium(I) Chemistry through Hemilability

We present a novel approach for constructing chains of Group 14 metal atoms linked by unsupported metal-metal bonds that exploits hemilabile ligands to generate unsaturated metal sites. The formation/nature of catenated species (oligo-dimetallynes) can be controlled by the use of (acidic/basic) "protecting groups" and through variation of the ligand scaffold. Reduction of ArNiPr2 GeCl (ArNiPr2 =2,6-(i Pr2 NCH2 )2 C6 H3 )-featuring hemilabile Ni Pr2 donors-yields (ArNiPr2 Ge)4 (2), which contains a tetrameric Ge4 chain. 2 represents a novel type of a linear homo-catenated GeI compound featuring unsupported E-E bonds. Trapping experiments reveal that a key structural component is the central two-way Ge=Ge donor-acceptor bond: reactions with IMe4 and W(CO)5 (NMe3 ) give the base- or acid-stabilized digermynes (ArNiPr2 Ge(IMe4 ))2 (4) and (ArNiPr2 Ge{W(CO)5 })2 (5), respectively. The use of smaller N-donors leads to stronger Ge-N interactions and quenching of catenation behaviour: reduction of ArNEt2 GeCl gives the digermyne (ArNEt2 Ge)2 , while the unsymmetrical system ArNEt2 GeGeArNiPr2 dimerizes to give tetranuclear (ArNEt2 GeGeArNiPr2 )2 through aggregation at the Ni Pr2 -ligated GeI centres.

(N),C,N-Coordinated Heavier Group 13-15 Compounds: Synthesis, Structure and Applications

The aim of this review is to summarize recent achievements in the field of (N),C,N-coordinated group 13-15 compounds not only regarding their synthesis and structure, but mainly focusing on their potential applications. Relevant compounds contain various types of N-coordinating ligands built up on an ortho-(di)substituted phenyl platform. Thus, group 13 and 14 derivatives were used as single-source precursors for the deposition of semiconducting thin films, as building blocks for the preparation of high-molecular polymers with remarkable optical and chemical properties or as compounds with interesting reactivity in hydrometallation processes. Group 15 derivatives function as catalysts in the Mannich reaction, in the allylation of aldehydes or activation of CO₂ . They were used as transmetallation reagents in transition metal catalysed coupling reactions. The univalent species serve as ligands for transition metals, activate alkynes or alkenes and are utilized as catalysts in the transfer hydrogenation of azo-compounds.

Current advances in tin cluster chemistry

This perspective summarizes highlights and most recent advances in tin cluster chemistry, thereby addressing the whole diversity of (mostly) discrete units containing tin atoms. Although being a (semi-)metallic element, tin is in the position to occur both in formally positive or negative oxidation states in these molecules, which causes a broad range of fundamentally different properties of the corresponding compounds. Tin(iv) compounds are not as oxophilic and not as prone to hydrolysis as related Si or Ge compounds, hence allowing for easier handling and potential application. Nevertheless, their reactivity is high due to an overall reduction of bond energies, which makes tin clusters interesting candidates for functional compounds. Beside aspects that point towards bioactivity or even medical applications, materials composed of naked or ligand-protected tin clusters, with or without bridging ligands, show interesting optical, and ion/molecule-trapping properties.

Recent advances in the self-assembly of polynuclear metal–selenium and –tellurium compounds from 14–16 reagents

The use of reagents containing bonds between group 14 elements and Se or Te for the self-assembly of polynuclear metal–chalcogen compounds is covered. Background material is briefly reviewed and examples from the literature are highlighted from the period 2007–2017. Emphasis is placed on the different classes of 14–16 precursors and their application in the targeted synthesis of metal–chalcogen compounds. The unique properties arising from the combination of specific 14–16 precursors, metal atoms, and ancillary ligands are also described. Selected examples are chosen to underline the progress in (i) controlled synthesis of heterometallic (ternary) chalcogen clusters, (ii) chalcogen clusters with organic functionalized surfaces, and (iii) crystalline open-framework metal chalcogenides.

Novel mono- and bimetallic organotin(iv) compounds as potential linkers for coordination polymers

Organotin(iv) compounds might be used as linkers for building coordination polymers as suggested by the isolation of [{2-(OCH)C₆H₄}Me₂SnO(O)CC₅H₄N-4]ZnTPP.

Rational Syntheses and Serendipity: Complexes [LSnPtCl2 (SMe2 )]2 , [{LSnPtCl(SMe2 )}2 SnCl2 ], [(LSn)3 (PtCl2 )(PtClSnCl){LSn(Cl)OH}], and [O(SnCl)2 (SnL)2 ] with L=MeN(CH2 CMe2 O)2

Syntheses and molecular structures of the dimeric tin-platinum complex [LSnPtCl₂ (SMe₂ )]₂ (2), the tin-platinum clusters [{LSnPtCl(SMe₂ )}₂ SnCl₂ )] (3) and [(LSn)₃ (PtCl₂ )(PtClSnCl)(LSnOHCl)] (6) (L=MeN(CH₂ CMe₂ O^- )₂ ), and of the unprecedented tin(II) aminoalkoxide-tin oxide chloride complex [O(SnCl)₂ ⋅(SnL)₂ ] (5) are reported. The compounds were characterized by NMR spectroscopy (¹ H, ¹³ C, ¹¹⁹ Sn, ¹⁹⁵ Pt), ¹¹⁹ Sn Mössbauer spectroscopy (1-3, 6), electrospray ionization mass spectrometry, elemental analyses, and single-crystal X-ray diffraction analyses (2⋅CH₂ Cl₂ , 3⋅2 C₄ H₈ O, 5, 6⋅3CH₂ Cl₂ ). The tin(II) aminoalkoxide [MeN(CH₂ CMe₂ O)₂ Sn]₂ (1) behaves like a neutral ligand, inserts into a Pt-Cl bond, or is involved in rearrangement reactions with the different behavior occurring even within one compound (3, 6). DFT calculations show that the tin-platinum compounds behave like electronic chameleons.

Homolytic, Heterolytic, Mesolytic - As You Like It: Steering the Cleavage of a HC(sp3 )-C(sp3 )H Bond in Bis(1H-2,1-benzazaborole) Derivatives

A set of (3,3')-bis(1-Ph-2-R-1H-2,1-benzazaborole) compounds, in which R=tBu (Bab-tBu)₂ , R=Dipp (Bab-Dipp)₂ or R=tBu and Dipp (Bab-Dipp)(Bab-tBu), was synthesized and fully characterized using ¹ H, ¹¹ B, ¹³ C, and ¹⁵ N NMR spectroscopy as well as single-crystal X-ray diffraction analysis. The central HC(sp³ )-C(sp³ )H bond with restricted rotation at the junction of both 1H-2,1-benzazaborole rings displayed an intriguing reactivity. It was demonstrated that this bond is easily mesolytically cleaved using alkali metals to form the respective aromatic 1Ph-2R-1H-2,1-benzazaborolyl anions M⁺ (THF)_n (Bab-tBu)^- (M=Li, Na, K) and K⁺ (THF)_n (Bab-Dipp)^- . Furthermore, the central HC(sp³ )-C(sp³ )H bond of bis(1H-2,1-benzazaborole)s is also homolytically cleaved either by heating or photochemical means, giving corresponding 1Ph-2R-1H-2,1-benzazaborolyl radicals (Bab-tBu)^. and (Bab-Dipp)^. , which rapidly self-terminate. Nevertheless, their formation was unambiguously established by NMR analysis of the reaction mixtures containing products of the self-termination of the radicals after heating or irradiation. (Bab-Dipp)^. radical was also characterized using EPR spectroscopy. Importantly, it turned out that the essentially non-polarized HC(sp³ )-C(sp³ )H bond in (Bab-tBu)₂ is also cleaved heterolytically with 2 equiv of MeLi, giving the mixture of Li⁺ (SOL)_n (Bab-tBu)^- (SOL=THF or Et₂ O) and lithium methyl-substituted borate complex Li⁺ (SOL)_n (Bab-tBu-Me)^- in a diastereoselective fashion.

Reactivity Study of a Pyridyl-1-azaallylgermanium(I) Dimer: Synthesis of Heavier Ether and Ester Analogues of Germanium

The reactivity study of a pyridyl-1-azaallylgermanium(I) dimer LGe-GeL [1; L = N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)] with different stoichiometric ratios of elemental selenium and tellurium is described. The reactions of 1 with 1 equiv of selenium and tellurium afforded the first examples of heavier ether analogues of germanium, bis(germylene) selenide and telluride LGe(μ-E)GeL [E = Se (2) and Te (3)], respectively. Meanwhile, the reactions of 1 with 2 equiv of selenium and tellurium gave the heavier ester analogues LGe═E(μ-E)GeL [E = Se (4) and (5)]. All compounds have been characterized by X-ray crystallography and multinuclear NMR spectroscopy.

Synthesis and Thorough Investigation of Discrete Organotin Telluride Clusters

Systematic experimental and theoretical investigations of reactions of R(1)SnCl3 (R(1) = CMe2CH2C(Me)O) with (Me3Si)2Te allowed for the stepwise formation and single-crystalline isolation of the first tin sesquitelluride clusters with functional organic ligands. Subsequent derivatization of the latter took place under reorganization of the inorganic core, affording clusters with complex hybrid architectures.

Antimony(III) and bismuth(III) amides containing pendant N-donor groups--a combined experimental and theoretical study

N,N- and N,N,N-chelated antimony(III) and bismuth(III) chlorides L(1-3)MCl2 1-4 [for L(1): M = Sb (1), for L(2): M = Sb (2) and for L(3): M = Sb (3) and Bi (4)], containing ligands L(1-3) derived from the pyrrole ring (where L(1) = C4H3N-2-(CH[double bond, length as m-dash]N-2',6'-iPr2C6H3), L(2) = C4H2N-2,5-(CH2NMe2)2, L(3) = C4H2N-2,5-(CH2NC4H8)2), were prepared by the treatment of lithium precursors with SbCl3 or BiCl3. Molecular structures 1-4 of were described both in solution (NMR spectroscopy) and in the solid state (single-crystal X-ray diffraction analysis). Structures of 1-4 were also subjected to a density functional theory study.

Functionalized organotin-chalcogenide complexes that exhibit defect heterocubane scaffolds: formation, synthesis, and characterization

The synthesis of new functionalized organotin-chalcogenide complexes was achieved by systematic optimization of the reaction conditions. The structures of compounds [(R(1, 2) Sn)3 S4 Cl] (1, 2), [((R(2) Sn)2 SnS4 )2 (μ-S)2 ] (3), [(R(1, 2) Sn)3 Se4 ][SnCl3 ] (4, 5), and [Li(thf)n ][(R(3) Sn)(HR(3) Sn)2 Se4 Cl] (6), in which R(1) =CMe2 CH2 C(O)Me, R(2) =CMe2 CH2 C(NNH2 )Me, and R(3) =CH2 CH2 COO, are based on defect heterocubane scaffolds, as shown by X-ray diffraction, (119) Sn NMR spectroscopy, and ESI mass spectrometry analyses. Compounds 4, 5, and 6 constitute the first examples of defect heterocubane-type metal-chalcogenide complexes that are comprised of selenide ligands. Comprehensive DFT calculations prompted us to search for the formal intermediates [(R(1) SnCl2 )2 (μ-S)] (7) and [(R(1) SnCl)2 (μ-S)2 ] (8), which were isolated and helped to understand the stepwise formation of compounds 1-6.

Mixed organotin(IV) chalcogenides: from molecules to Sn-S-Se semiconducting thin films deposited by spin-coating

Put the right spin on it: Mixed monomeric organotin(IV) chalcogenides of the general formula L(2)Sn(2)EX(2) containing two terminal Sn-X (X = Se, Te) bonds were prepared and were tested as potential single-source precursors for the deposition of semiconducting thin films. Spin-coating deposition of [{2,6-(Me(2)NCH(2))(2)C(6)H(3)}SnSe](2)(μ-S), as the useful single-source precursor, provided amorphous Sn-S-Se semiconducting thin films.