Tin(iv) and lead(iv) complexes with a tetradentate redox-active ligand

Abstract

The coordination chemistry of a tetradentate redox-active ligand, glyoxal-bis(2-hydroxy-3,5-di-tert-butylanil) (H(2)L), was investigated with the diorganotin(IV) and diphenyllead(IV) moieties. Complexes R(2)SnL (R = Me (1), Et (2), (t)Bu (3), Ph (4)) and Ph(2)PbL (5) have been prepared and characterized. The molecular structures of compounds 1, 3, and 5 have been determined by single crystal X-ray diffraction. The diamagnetic octahedral complexes bear a tetradentate O,N,N,O redox-active ligand with a nearly planar core. Complexes 1-5 demonstrate solvatochromism in solution. The CV of complexes 1-5 reveals four one-electron redox processes. The spin density distribution in the chemically generated cations and anions of 1-5 was studied by X-band EPR spectroscopy. The experimental data agree well with the results of DFT calculations of electronic structures for 1, its pyridine adduct 1·Py, cation 1(+) and anion 1(-).

A Sterically Hindered Derivative of 2,1,3‐Benzotelluradiazole: A Way to the First Structurally Characterised Monomeric Tellurium–Nitrogen Radical Anion

“…[20] For the ethylene-bridged congener of L, the radical-anion states were characterised by EPR spectroscopy,but structural data are lacking. [21] As as ummary to this introduction,w eb elieve that preparation of the Te complex with ligand L( which can alternatively be regarded as as terically hindered derivativeo f2 ,1,3-benzochalcogenadiazole)c an open an ew way to compounds with a telluradiazole-relatedf ragment and an open-shell electronic structure, which will be stabilised by two O-donor substituents that would protect the TeN 2 fragment against strong intermolecular ChB. Taking into account the scarcity of complexes of the main group elements with the tetradentate redox-active ligand L, as wella st he steadilyg rowing interesti nv arious aspects of the chemistry of heavier chalcogens, [22] we targeted compound Te L( 1)i no ur research.…”

“…Biradical nature of the dianionic ligand L 2− was proposed for SnL 2 , but it is believed that strong antiferromagnetic exchange interaction leads to the diamagnetic ground state of the entire complex [20] . For the ethylene‐bridged congener of L, the radical‐anion states were characterised by EPR spectroscopy, but structural data are lacking [21] …”

Theoretical investigation of the N → Sn coordination in (Me3SnCN)2

“…Moreover, the theoretical studies of the intermolecular N → Sn coordination in other organotin(IV) compounds are generally rare [43][44][45]. Therefore, the second goal of the present work is to provide insight into the intermolecular N → Sn coordination in the (Me 3 SnCN) 2 dimer.…”

Derivatives of penta-, hexa-, and hepta-coordinated tin with Schiff bases and 1,10-phenanthroline: structure, redox and optoelectronic properties

“…In this case, one of the most frequently used ligands (as in the coordination chemistry of other elements) are Schiff bases. 14,15 Despite the presence of a significant number of works devoted to the electrochemical behavior and UV-vis spectroscopy of tin coordination compounds, [16][17][18][19][20][21] the influence pattern of electron pair donors on the position of their frontier orbitals has hardly been discussed.…”