Jonathan Starbuck

The platinum catalysed diboration of alkynes using 1,2-B2Cl2(NMe2)2: formation of 1-azonia-2-borata-5-borole derivatives

The platinum catalysed diboration of alkynes using the diborane(4) compound 1,2-B2Cl2(NMe2)2 affords high yields of cyclic 1-azonia-2-borata-5-borole compounds, which arise from redistribution of B–Cl and B–NMe2 bonds.

Homologous families of chloride-rich 4,4′-bipyridinium salt structures

New layer and three-dimensional 4,4′-bipyridinium salts of Cl−, [MCl6]2− (M = Os, Pt) and [FeCl5]2− contain NH⋯(Cl)2⋯HN interactions which form hydrogen bonded ribbons which in turn give one-, two-, or three-dimensional periodic networks; two related families of homologous motifs are present in these salts together with those of square planar, polymeric and tetrahedral [MCl4]2− (M = Pt, Pd, Mn, Cd, Pb, Co, Zn, Hg), planar [Cu2Cl6]2− and square pyramidal [SbCl5]2− dianions.

Synthetic routes to cyclic and unsymmetric diborane(4) compounds

The reaction between 1,2-B2Cl2(NMe2)2 and disodium catecholate Na2[1,2-O2C6H4] affords the cyclic diborane(4) compound 1,2-B2(NMe2)2(cat) (cat=1,2-O2C6H4), whereas a similar reaction using dilithium thiocatecholate Li2[1,2-S2C6H4] affords the 1,1-isomer 1,1-B2(NMe2)2(thiocat) (thiocat=1,2-S2C6H4). Both compounds can be used to prepare unsymmetric diborane(4) species.

Synthesis and X-ray structure of a [4]ferrocenophane containing a boron-boron bond

Abstract The synthesis and X-ray crystal structure of the [4]ferrocenophane compound [1,2-B 2 (NMe 2 ) 2 {1,1′-(SC 5 H 4 ) 2 Fe}] which contains a B–B bond are described. The ferrocene-1,1′-dithiolate group bridges the B–B bond of the diborane(4) unit [B–B 1.709(9) A] in a 1,2- fashion. Each boron centre is trigonal planar, the angle between these planes being 82.0° such that the conformation about the B–B bond is staggered rather than eclipsed. All other angles fall within expected ranges indicating that there is little strain present in this compound.

Cation-controlled formation of [{MCl4}n]2n– chains in [4,4′-H2bipy][MCl4] (M = Mn, Cd): an alternative to the A2MCl4 layer perovskite structure†

The cis-MCl2‥HN+ chelated hydrogen bond synthon has been exploited in preparation of crystalline [4,4′- H2bipy][MCl4] (M = Mn 2 and Cd 3), which shows a one-dimensional substructure of the form [{MCl4}n]2n– consisting of a kinked chain of doubly edge sharing MCl6 octahedra. These chains are cross-linked by hydrogen bonding to the [4,4′-H2bipy]2+ ions.

Coordination complexes of the bismuth(III) thiolates Bi(SC6F5)3 and Bi(SC6Cl5)3 with pyridine ligands

The chloro-aryl bismuth thiolate Bi(SC6Cl5)3 has been prepared from the reaction between BiPh3 and the thiol HSC6Cl5 by analogy with the previously described synthesis of the fluoro-aryl species Bi(SC6F5)3. The compound Bi(SC6Cl5)3 is only sparingly soluble but can be isolated as a dmf adduct [Bi(SC6Cl5)3(dmf)2] (dmf = N,N-dimethylformamide) which adopts a five-coordinate square-based pyramidal geometry in which the two dmf ligands lie in the basal plane with a mutually cis configuration. Treatment of either Bi(SC6F5)3 or Bi(SC6Cl5)3 with pyridine or 2,2′-bipyridyl ligands affords the coordination complexes fac-[Bi(SC6F5)3(py)3] (two crystalline polymorphs), fac-[Bi(SC6Cl5)3(py)3], fac-[Bi(SC6F5)3(4-pic)3] (4-pic = 4-picoline), [Bi(SC6Cl5)3(4-pic)2], [Bi(SC6F5)3(bipy)] (bipy = 2,2′-bipyridyl), [Bi(SC6Cl5)3(bipy)], [Bi2(SC6Cl5)6(2-pic)3] (2-pic = 2-picoline) and [Bi(SC6F5)3(4-pic)]. Five- and four-coordinate complexes adopt square-based pyramidal and equatorially vacant, trigonal bipyramidal (disphenoidal) geometries respectively, the former having the two ligands cis to each other in the basal plane. The compound [Bi2(SC6Cl5)6(2-pic)3] contains both five- and four-coordinate mononuclear units. A salt with the formula [4-picH][(4-pic)2H][Bi3(SC6F5)11] was also isolated in which the anion contains a central bismuth bonded to five thiolate ligands with a square-based pyramidal geometry. Two cis-basal thiolates act as bridging groups to two outer bismuth centres each of which is four-coordinate with the expected disphenoidal geometry in which the bridging thiolate is in an axial position. The structure of the dinuclear arylbismuth thiolate compound [Bi2Ph2(SC6F5)4(4-pic)2] is also described. Intramolecular conformations and intermolecular associations in all structures are dominated by π–π-interactions.

Tetra­methyl­ammonium di­chloro­di­phenyl­bismuthate(III)

The crystal structure of the title compound, (C4H12N)[BiCl2(C6H5)2], contains a [BiCl2Ph2]− anion with an equatorially vacant trigonal-bipyramidal geometry.