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The coordination capability of two N,C,N pincer coordinated stibinidenes, i. e. bis(imino)‐ [2,6‐(DippN=CH)2C6H3]Sb (1) or imino‐amino‐ [2‐(DippN=CH)‐6‐(DippNHCH2)C6H3]Sb (2) toward palladium(II) and platinum(II) centers was examined. In the course of this study, seven new square‐planar bis(stibinidene) complexes were synthesized and characterized by NMR, IR, Raman, UV‐vis spectroscopy and single crystal (sc)‐X‐ray diffraction analysis. In all cases, both stibinidene ligands 1 or 2 adopt trans positions, but differ significantly in the torsion angle describing mutual orientation of aromatic rings of the stibinidenes along the Sb−Pd/Pt−Sb axes. Furthermore, majority of complexes form isomers in solution most probably due to a hindered rotation around Sb−Pd/Pt bonds caused by bulkiness of 1 and 2. This phenomenon also seems to be influenced by the absence/presence of a pendant −CH2NH− group in 1/2 that is able to form intramolecular hydrogen bonds with the adjacent chlorine atom(s) attached to the metal centers. The whole problem was subjected to a theoretical study focusing on the role of hydrogen bonds in structure architecture of the complexes. To describe the UV‐vis spectra of these highly coloured complexes, TD‐DFT calculations were employed. These outline differences between the stibinidene ligands, the transition metals as well as between the charge of the complexes (neutral or anionic). [ABSTRACT FROM AUTHOR]

In this study, Ru complexes [(η6‐p‐cymene)RuX(2‐{(2,6‐iPr2‐C6H3)N=CH}‐C5H3N‐6‐(O))] (3: X=Cl; 4: X=I) were prepared with N‐bound 2‐pyridonato ligand by thermal base‐free MeX elimination from ionic N,N‐chelated Ru complexes [(η6‐p‐cymene)RuX(κ2‐L1)](X) (1: X=Cl; 2: X=I; L1={2‐[(2,6‐iPr2‐C6H3)N=CH]‐6‐(OMe)C5H3N}). The Ru complex 3 was used as O‐donor for Lewis (LA) or Brönsted acids. The reactions of 3 with SnCl2, Ph3SnCl, ZnCl2 or HCl provided [(η6‐p‐cymene)Ru(SnCl3)(2‐{(2,6‐iPr2‐C6H3)N=CH}‐C5H3N‐6‐(O→SnCl2)] (6), [(η6‐p‐cymene)RuCl(2‐{(2,6‐iPr2‐C6H3)N=CH}‐C5H3N‐6‐(O→SnPh3Cl)] (7), and [(η6‐p‐cymene)RuCl(2‐{(2,6‐iPr2‐C6H3)N=CH}‐C5H3N‐6‐(O→)]2(μ‐ZnCl2) (8) and [(η6‐p‐cymene)RuCl(2‐{(2,6‐iPr2‐C6H3)N=CH}‐C5H3N‐6‐(OH)}](Cl) (9). The easy conversion of the 2‐pyridonato ligand in 3 to its 2‐hydroxypyridine in 9 evoked testing of 3 and 4 as potential catalysts in base‐free transfer‐hydrogenation of ketones. [ABSTRACT FROM AUTHOR]

This study reports the synthesis and characterization of new molybdenum compounds bearing benz[e]indenyl and benz[f]indenyl ligands. The capability of the ligands to undergo η5-to-η3 haptotropic rearrangement was evidenced on reactions with tris(pyrazolyl)methane. Appearance of the η3-coordination mode was determined by NMR spectroscopy and X-ray structure analysis on a single crystal. [ABSTRACT FROM AUTHOR]

1-Boryl-8-phosphinonaphthalenes 1-BCy2-8-PCl2-C10H6 (1) and 1-BCy2-8-PPhCl-C10H6 (2) were prepared and used as starting materials for the synthesis of B-substituted phosphides. The reduction of 1 and 2 by Mg provided neutral compounds [1-BCy-8-PCy-C10H6]2 (3) and [1-BCy2-8-PPh-C10H6]2 (4). Compound 3 represents the dimer of phosphinoborane 1-BCy-8-PCy-C10H6 while complex 4 is a rare example of a discrete B ← P coordinated diphosphine. The reduction of 2 by Na or K in THF yielded B-substituted group 1 phosphides [Na(THF)3]+[1-BCy2-8-PPh-C10H6]− (5) and {[K(THF)2]+[1-BCy2-8-PPh-C10H6]−}∞ (6), which structurally resembled bulky group 1 phosphides. Complex 5 showed easy activation of elemental chalcogens E (E = O, S, Se) to give B-substituted chalcogenophosphinites {[Na(THF)2]+[1-BCy2-8-P(E)Ph-C10H6]}2 (E = O (7), S (8), Se (9)) as the products of chalcogen insertion into the P–Na bond. Importantly no oxidation to dichalcogenophosphinates was observed. Compound 5 is tolerant of the CO polar bonds in organic substrates and the reactions of 5 with 2,3-butanedione or an acyl chloride provided {[Na(THF)2]+[1-BCy2-8-P{CHC(O)C(Me)O}Ph-C10H6]−}2 (10) and [1-BCy2-8-P{C(O)tBu}Ph-C10H6] (11). Finally, B-coordinated phosphatetrylenes [1-BCy2-8-P(SnL)Ph-C10H6] (12) and [1-BCy2-8-P(PbL)Ph-C10H6] (13) (L is {2,6-(Me2NCH2)C6H3}−) were also prepared by substitution reactions of 5. [ABSTRACT FROM AUTHOR]

A set of N-coordinated tellurium(II) compounds containing either C,N-chelating ligands CNR (where CN = 2-(RN＝CH)C6H4, R = tBu or Dipp; Dipp = 2,6-iPr2C6H3) or N,C,N pincer ligands NCNR (where NCN = 2,6-(RN＝CH)2C6H4, R = tBu or Dipp) were synthesized. In the case of C,N-chelated compounds, the reaction of CNDippLi with Te(dtc)2 (where dtc = Et2NCS2) in a 1 : 1 molar ratio smoothly provided the carbamate CNDippTe(dtc) which upon treatment with 2 eq. of HCl provided the chloride CNDippTeCl. In contrast, the analogous conversion of NCNRLi with Te(dtc)2 surprisingly furnished ionic bromides [NCNRTe]Br as a result of the exchange of dtc by Br coming from nBuBr present in the reaction mixture. Furthermore, the reaction of CNDippTeCl or [NCNRTe]Br with silver salts AgX (X = OTf or SbF6) provided the expected tellurenium cations [CNDippTe]SbF6 and [NCNRTe]X. To further increase the Lewis acidity of the central atom, the oxidation of selected compounds with 1 eq. of SO2Cl2 was examined yielding stable compounds [CNtBuTeCl2]X and [NCNtBuTeCl2]X. The oxidation of the Dipp substituted compounds proved to be more challenging and an excess of SO2Cl2 was necessary to obtain the oxidized products [CNDippTeCl2]SbF6 and [NCNDippTeCl2]SbF6, which could solely be characterized in solution. Compounds [CNtBuTeCl2]OTf and [NCNtBuTeCl2]OTf were shown to undergo a controlled hydrolysis to the corresponding telluroxanes. All compounds were studied by multinuclear NMR spectroscopy in solution and for selected compounds solid state 125Te NMR spectroscopy and single-crystal X-ray diffraction analysis were performed. The Lewis acidity of the studied cations was examined by the Gutmann–Beckett method using Et3PO as the probing agent. The Te–N chalcogen bonding situation of selected compounds has also been examined computationally by a set of real-space bonding indicators. [ABSTRACT FROM AUTHOR]

N‐coordinated Ge(II) alkoxides L1(tBuO)Ge (1), L2(tBuO)Ge (2) and [L2(OtBu)Ge ⋅ BH3] (4) were prepared. Effect of either chelating ligands L1 and L2 or Ge→B interaction on strength of the Ge−OtBu bond was studied by insertion reaction of PhNCO. As a result, the Ge(II) carbamate L2{[(tBuO)OC](Ph)N}Ge (3) was isolated. Alcoholysis exchange reactions of 1 and 2 with substituted phenols were studied to find an easy synthetic protocol for a synthesis of functionalized Ge(II) alkoxides. Reactions yielded Ge(II) alkoxides L1,2(2‐Br−C6H4O)Ge (5 for L1, 8 for L2), L1,2(2‐MeNH−C6H4O)Ge (6 for L1, 9 for L2), L1,2(2‐Ph2P−C6H4O)Ge (7 for L1, 10 for L2), L2(2‐Br‐3‐OH−C6H3O)Ge (11) and L2(2‐NC5H4O)Ge (12) containing the additional polar groups Y (Y=Br, MeNH, PPh2, OH or N). Finally, phosphane decorated Ge(II) alkoxides 7 and 10 were tested as suitable ligands in reactions with (COD)W(CO)4 and BH3. As a consequence, new complexes [(κ2‐7)W(CO)4] (13) and [L1(2‐Ph2P ⋅ {BH3}‐C6H4O)Ge ⋅ {BH3}] (14) were isolated. All compounds were characterized by NMR and IR spectroscopy, and compounds 3, 4, 9 and 11 were additionally characterized by X‐ray diffraction analysis. [ABSTRACT FROM AUTHOR]

The oxidative addition of CF3SO3CH2Si(CH3)3 (NpSiOTf) toward organopnictogen(I) N,C,N-pincer compounds, i.e. [2,6-(DippN＝CH)2C6H3]E (1-E, where E = Sb, Bi; Dipp = 2,6-iPr2C6H3) produced compounds [2,6-(DippN＝CH)2C6H3]E(NpSi)(OTf) (2-E, where E = Sb, Bi). By analogy, the in situ reduction of [2,6-(Me2NCH2)2C6H3]ECl2 (3-E, where E = Sb, Bi) followed by treatment with NpSiOTf or MeI gave compounds [2,6-(Me2NCH2)2C6H3]E(R)(X) (R/X = NpSi/OTf 4-E, where E = Sb, Bi; R/X = Me/I 5-Sb). The reactivity of these compounds toward 1 eq. of K[BEt3H] was examined showing remarkable differences depending both on the ligand backbone and the pnictogen used. Thus in the case of 2-E, the addition of the hydride across the imino-function was achieved thereby yielding azapnicta-heterocyclic compounds [2-(DippNCH2)-6-(DippN＝CH)C6H3]E(NpSi) (6-E, where E = Sb, Bi). The same reaction of 4-Bi produced dibismuthine {[2,6-(Me2NCH2)2C6H3]Bi(NpSi)}2 (7-Bi), but in the case of 4/5-Sb the analogous distibines {[2,6-(Me2NCH2)2C6H3]Sb(R)}2 (R = NpSi7-Sb, Me 8-Sb) were not formed directly and hydrides [2,6-(Me2NCH2)2C6H3]Sb(R)H (R = NpSi9-Sb, Me 10-Sb) could be isolated instead. Nevertheless, heating of both 9-Sb and 10-Sb led to an activation of a labile Sb–H bond and the formation of distibines 7/8-Sb. [ABSTRACT FROM AUTHOR]