Surajit Jana

First mixed hydrazide/hydroxylamide metal aggregates.

The first organometallic clusters of mixed hydrazide/hydroxylamide clusters of zinc, [Zn(MeZn)(4)(HNNMe(2))(2)(ONEt(2))(4)] and {Zn(EtZn)(4)[HNN(CH(2))(5)](2)(ONEt(2))(4)} were synthesized in one-pot synthesis protocols from dialkylzinc solutions, substituted hydrazines and N,N-diethylhydroxylamine; competing for the Zn atoms, the different binding properties of hydrazide and hydroxylamide ligands in these heteroleptic clusters are discussed.

Organozinc Siloxide-Hydrazide Aggregates [(RZn)4(NHNMe2)x(OSiMe3)(4 – x)]

The reaction of dialkylzinc compounds R2Zn (R = Me, Et) with N,N-dimethylhydrazine and trimethylsilanol in a 4 : 2 : 2 ratio leads to the formation of tetra(alkylzinc) tris-siloxide monohydrazide aggregates, [(RZn)4(NHNMe2)(OSiMe3)3] [R = Me (1) and Et (2)]. These compounds are aggregates of mirror symmetry, containing the novel Zn4N2O3 core. Both compounds have been characterised by 1H, 13C and 29Si NMR and IR spectroscopy, by mass spectrometry and by elemental analysis, and 2 also by X-ray crystallography. The structure can be derived from a heterocubane, in which one anionic vertex is replaced by an NHNMe2 group contributing two N atoms to the core constitution. By applying a ratio of hydrazine : silanol of 2 : 1 in a reaction with R2Zn (R = Me, Et, iPr), compounds of the general formula [(RZn)4(NHNMe2)2(OSiMe3)2] [R = Me (3), Et (4), iPr (5)] are obtained. These aggregates contain a Zn4N4O2 core. Upon employing a hydrazine : silanol ratio of 5 : 1 in a reaction with diisopropyl zinc, the compound [(iPrZn)4(NHNMe2)3(OSiMe3)] results, containing a Zn4N6O unit. Compounds 3 - 6 have been characterised by 1H, 13C and 29Si NMR and IR spectroscopy, by mass spectrometry and by elemental analysis. The topologic relationship between the pure hydrazides [(RZn)4(NHNMe2)4], the mixed aggregates [(RZn)4(NHNMe2)3(OR’)], [(RZn)4(NHNMe2)2(OR’)2] and [(RZn)4(NHNMe2)3(OR’)3] and the pure alkoxides [(RZn)4(OR’)4] is discussed.

Basic Beryllium ortho-Fluorobenzoate and its Mono-hydroxo Derivative

The preparation of tetraberyllium-μ4-oxo-hexa[η2-(ortho-fluorobenzoate)] [Be4O(o-C6H4FCOO) 6, 2] and tetraberyllium-μ4-oxo-μ2-hydroxo-penta[η2-(ortho-fluorobenzoate)] [Be4(o-C6H4F-COO)5(OH), 3] from silver ortho-fluorobenzoate and BeCl2 in Et2O/thf solution containing varying amounts of water is reported. The single-crystal structures of 2·tetrahydrofuran and 3·Et2O·2 hexane are discussed in comparison with the structure of the known basic beryllium and zinc carboxylates [M4O(RCOO)6, M = Be, Zn]. DFT calculations show that lower symmetry has to be expected for Be-based M4O-framework-type compounds as compared to the corresponding Zn compounds. Compound 2 is a potential precursor for new compounds with MOF substructure motifs Graphical Abstract Basic Beryllium ortho-Fluorobenzoate and its Mono-hydroxo Derivative

An Organozinc Hydrazide-Thiolate Aggregate with a Zn3N4S2 Core

The first organometallic zinc hydrazide-thiolate cluster, [(MeZn)2(PhSZn)(HNNMe2)(H2N-NMe2)(SPh)2]2 (1) has been prepared by alkane elimination from dimethylzinc solutions upon treatment with N,N-dimethylhydrazine and thiophenol and characterised by NMR spectroscopy, elemental analysis and single crystal X-ray diffraction. Compound 1 forms asymmetric aggregates containing a Zn3N4S2 core. The core features rings with different connectivities. A seven-membered ZnSZnNNZnS ring comprises three fivemembered rings, two of a ZnSZnNN and one of a ZnNZnNN atom sequence. Intermolecular S···H bonding is observed in the crystal. Graphical Abstract An Organozinc Hydrazide-Thiolate Aggregate with a Zn3N4S2 Core

Simple Methylcadmium Alkoxides

The reaction of dimethylcadmium with alcohols R-OH in equimolar ratio leads to the formation of tetrameric methylcadmium alkoxides with molecular formula [(MeCd)4 (OR)4] [R = Me (1), Et (2) and iPr (3)]. These compounds have been characterised by 1H, 13C NMR and IR spectroscopy, by mass spectrometry, elemental analyses and by X-ray crystallography (for 2 and 3). The solid state structures show distorted cubane-type aggregates with Cd4O4 cores. The structural aspects and the spectroscopic characterisations of these compounds are discussed.

A diethylhydroxylaminate based mixed lithium/beryllium aggregate

Abstract A mixed lithium/beryllium diethylhydroxylaminate compound containing nbutyl beryllium units of total molecular composition nBe(ONEt2)2 [(LiONEt2)2 nBuBeONEt2]2 (1) was isolated from a reaction mixture of nbutyl lithium, N,N-diethylhydroxylamine and BeCl2 in diethylether/thf. The crystal structure of 1 has been determined by X-ray diffraction. The aggregate is composed of two ladder-type subunits connected in a beryllium-centered distorted tetrahedron of four oxygen atoms. Only the lithium atoms are engaged in coordination with the nitrogen donor atoms. The DFT calculations support the positional occupation determined for Li and Be in the crystal structure. The DFT and the solid-state structure are in excellent agreement, indicating only weak intermolecular interactions in the solid state. Structural details of metal atom coordination are discussed.

Bis(μ-diisopropyl­hydoxylaminato)-κ2O:N;κ2O:O-bis­[(diisopropyl­hydoxylaminato-κO)beryllium]

The title compound, [Be2(C6H14NO)4], was prepared from a solution of BeCl2 in diethyl ether and two equivalents of O-lithiated N,N-diisopropylhydoxylamine. The molecular structure is composed of a dinuclear unit forming a central five-membered planar Be—O—Be—O—N ring (sum of internal angles = 540.0°; r.m.s. deviation from planarity = 0.0087 Å). Both Be atoms show the unusual coordination number of three, with one Be atom coordinated by three O atoms and the other by two O atoms and one N atom, both in distorted trigonal–planar environments. The Be—O distances are in the range 1.493 (5)–1.600 (5) Å and the Be—N distance is 1.741 (5) Å.