Richard A. Varga

Hypervalent organotin(IV) derivatives containing [2-(Me2NCH2)C6H4]Sn moieties. Competition between nitrogen and chalcogen atoms for coordination to the metal centre

Abstract [2-(Me2NCH2)C6H4]SnPh2Cl (1) was prepared by reacting Ph2SnCl2 with [2-(Me2NCH2)C6H4]Li in toluene. The reactions of (1) with the ammonium salt of the appropriate thiophosphinato ligand in 1:1 molar ratio afford the isolation of [2-(Me2NCH2)C6H4]SnPh2L [L=S(S)PPh2 (2), O(S)PPh2 (3)] as white crystalline solids. The molecular structure of 1–3 was determined by single-crystal X-ray diffraction. Their crystals contain monomeric units with the metal atom exhibiting a distorted trigonal bipyramidal coordination environment. The SnC3 moiety is almost planar. The N atom of the pending CH2NMe2 arm is strongly coordinated to the metal centre (Sn(1)N(1) 2.519(2), 2.548(3), 2.481(2) A for 1, 2 and 3, respectively), trans to the Cl, O or S atoms (N(1)Sn(1)Cl(1) 170.49(6)°, N(1)Sn(1)S(1) 169.06(8)°, N(1)Sn(1)O(1) 168.58(8)°, respectively). The S atom double bonded to phosphorus is not involved in intra- or intermolecular coordination to tin.

Organolead(IV) derivatives of oxophosphorus ligands.: X-ray structures of monomeric R2Pb[(OPPh2)2N]2 (R=Me, Ph) and tetrameric [Me3Pb(O2PPh2)]4

Abstract The reaction of R4−nPbCln with Na[(OPPh2)2N] or K[(OPPh2)(SPPh2)N] afforded isolation of Ph2Pb[(OPPh2)2N]2 (1), Ph2Pb[(OPPh2)(SPPh2)N]2 (2), Me3Pb[(OPPh2)2N] (3) and Ph3Pb[(OPPh2)(SPPh2)N] (4). Attempts to grow crystals of Me3Pb[(OPPh2)2N] (3) led to isolation of Me2Pb[(OPPh2)2N]2 (5), as a result of decomposition. Me3Pb(O2PPh2) (6) was obtained from Me3PbCl and Na(O2PPh2). The compounds were characterized by IR and multinuclear NMR spectroscopy. The molecular structures of 1, 5 and 6 were determined by single-crystal X-ray diffraction. The crystal of 5 contains two independent molecules in the unit cell. In both compounds the imidodiphosphinato ligands act as monometallic biconnective units, resulting in a spiro-bicyclic system with six-membered PbO2P2N rings of distorted boat conformation. The coordination geometry around the metal atom is distorted octahedral, with CPbC angles close to 180° [178.9(2)° for 1; 173.4(3)° and 178.7(4)° for molecules 5a and 5b, respectively]. The crystal of the trimethyllead(IV) phosphinate (6) contains discrete tetrameric units, [Me3Pb(O2PPh2)]4, with bridging phosphinato ligands [range: PbO 2.373(3)–2.402(6) A, PO 1.495(6)–1.512(6) A], thus resulting in a sixteen-membered Pb4O8P4 inorganic ring. The coordination geometry at lead atoms is distorted trigonal bipyramidal, with oxygen atoms in trans positions [range: OPbO 174.7(2)–177.6(3)°].

Tris[2-(morpholin-4-ylmethyl)phenyl-κ2C1,N]antimony(III)

The title compound, [Sb(C11H14NO)3], is monomeric with the Sb atom located on a threefold axis. The complex exhibits distorted trigonal-antiprismatic geometry around the Sb atom, owing to the presence of intramolecular N-->Sb interactions. H...phenyl intermolecular interactions lead to the formation of dimers stacked along the c axis. The morpholine rings exhibit almost ideal chair conformations. No intermolecular interactions between the morpholine rings of neighbouring molecules were observed.

Synthesis and Spectroscopic Characterization of New Organolead(Iv) Complexes Containing Organophosphorus Ligands

Abstract Organolead(IV) derivatives of organophosphorus ligands, RnPb[(OPPh2)(SPPh2)N]4-n (R = Ph; n = 2, 3) and Me3Pb[S2PR2] (X = S, O; R = Me, Et, Ph), were prepared by reacting the corresponding organolead(IV) chloride with the sodium, potassium or ammonium salt of the appropriate organophosphoric acid. The title compounds were investigated by IR and multinuclear (1H, 13C, 31P) NMR spectroscopy, and possible structures are proposed. All dithiophosphinato complexes exhibited low stability and underwent decomposition on standing. The decomposition process was monitored by using 1H and 31P NMR spectroscopy, and a decomposition pathway is proposed.

Substitutional disorder in a hypervalent diorganotin(IV) dihalide

The structure of bromidochloridobis[2-(dimethylaminomethyl)phenyl]tin(IV), [SnBr0.65Cl1.35(C9H12N)2], contains two 2-(Me2NCH2)C6H4 units bonded to a Sn atom which lies on a twofold axis. The compound exhibits substitutional disorder of the halide atoms bonded to the Sn, with 1.35 occupancy for Cl and 0.65 for Br; it is isomorphous with the corresponding dichloride. The Sn atom is hexacoordinated with a (C,N)2SnX 2 (X = Cl/Br) distorted octahedral core as a result of the strong intramolecular N→Sn coordination trans to the Sn—X bonds (N1—Sn1—X1 = 165.8°). As a result of the intermolecular contacts, viz. H⋯X and H⋯benzene interactions, the molecules are arranged in a three-dimensional supramolecular manner in the crystal structure.

Inorganic Chelate Rings in Organolead(IV) Derivatives of Organophosphorus Ligands from 6-Membered to 16-Membered Rings

New organolead(IV) complexes of the type R3Pb[(OPPh2)(XPPh2)N], R2Pb[(OPPh2)(XPPh2)N]2 (R = Me, Ph; X = O, S) and Me3Pb(O2PPh2) have been prepared and characterized by IR and multinuclear (1H, 13C, 31P) NMR spectroscopy. The X-ray molecular structure of the Me2Pb[(OPPh2)2N]2 and Me3Pb(O2PPh2) is discussed.

[2,6-Bis(dimethyl-amino-meth-yl)phen-yl]selenium bromide monohydrate.

In the title hydrated molecular salt, C12H19N2Se+·Br−·H2O, the two independent bromide anions lie on a twofold rotation axis. Strong intramolecular N→Se interactions [2.185 (3) and 2.181 (3) Å] are established by both N atoms of the organic group in the cation, in trans positions to each other, with an N—Se—N angle of 161.6 (1)°, resulting in a T-shaped (C,N,N′)Se core. In the crystal, dimeric associations are formed by Br⋯Se [3.662 (2) Å] and Br⋯H interactions [2.56 (6) and 2.63 (7) Å] involving two bromide anions, two cations and two water molecules.

Crystal Structure of Triphenyltin(IV) Diphenyldithiophosphinate

Figure 1. Molecular structure of I (hydrogen atoms are omitted for clarity): Selected bond distances (A) and angles (°): Sn-Sl 2.452(1), Sn-S2 3.649(2), S l P l 2.082(1) S2-P1 1.945(1), C l S n S l 112.30(8), C7-SnS1 113.15(10), C13-Sn-Sl 100.10(9), C l -Sn -C7 111.38(12), C13-Sn-C7 107.57(13), Cl -Sn-C13 111.74(12),C1-Sn-S2 80.26(8), C7-Sn-S2 76.90(0), C13-Sn-S2 163.34(9), S l -Sn -S2 63.87(3).

Butyl­trichlorido{2-[(diisopropyl­ammonio)­meth­yl]phen­yl}tin(IV) dichloro­methane monosolvate

The title compound, [Sn(C4H9)(C13H21N)Cl3]·CH2Cl2, was obtained by recrystallization of [2-(diisopropylaminomethyl)phenyl]tin(IV) butyl dichloride from a CH2Cl2/n-hexane mixture (1:4 v/v) in the presence of ambient moisture. Partial hydrolysis led to the title compound, the hydrochloric acid adduct of the dichloride, having a pentacoordinated Sn atom with a trigonal–bipyramidal C2SnCl3 core. The N atom of the 2-[(diisopropylammonio)methyl]phenyl ligand forms a strong intramolecular N—H⋯Cl hydrogen bond, resulting in a zwitterionic species, [2-(iPr2HN+CH2)C6H4]SnBuCl3 −·CH2Cl2. Disorder was found in the n-butyl group, which was refined as disordered over three positions, with site occupancies of 0.22 (1), 0.51 (1) and 0.27 (2).

A new ortho­rhom­bic polymorph of 1,1′-seleno­bis­(N,N-diethyl­sulfanecarbothio­amide)

The title compound [systematic name: N,N-diethyl({[(diethylcarbamothioyl)sulfanyl]selanyl}sulfanyl)carbothioamide], C10H20N2S4Se, crystallizes in a new form in the space group Pca21: the previously reported polymorph crystallizes in the space group P212121. The new phase contains two independent molecules in the asymmetric unit. The Se atoms are tetracoordinated, with a distorted square-planar geometry. The ligands coordinate asymmetrically to the Se atoms, with one strong Se—S bond [range 2.2833 (13)–2.3041 (15) Å] and one weaker bond [range 2.7318 (14)–2.7873 (12) Å].