Anthony G. Mackie

The structure of triphenylphosphorus–diiodine, Ph3PI2, the first crystallographically characterised dihalogen derivative of a tertiary phosphine

Triphenylphosphine reacts with diiodine in dry diethyl ether to produce Ph3PI2, shown by X-ray crystallography to be a molecular four-coordinate compound Ph3P–I–I, and not the five-coordinate Ph3PI2 or the ionic [Ph3PI]+I–, previously thought to be the only possible solid-state structures for such a compound.

The structure of triphenylphosphorus–dibromine, the first crystallographically characterised bromophosphorane, a compound which has the novel four-coordinate molecular Ph3P–Br–Br geometry

Triphenylphosphorus–dibromine is shown by X-ray crystallography to have a four-coordinate Ph3P–Br–Br ‘spoke’ structure and is isostructural with Ph3P–I–I and Ph3As–I–I; thus forcing us to question the conventional belief that tertiary-organo group 15 adducts with dihalogens have either pentacoordinate R3EX2 or ionic [R3EX]+X– structures in the solid state.

The coordination chemistry of manganese. : Part VII. The preparation and spectroscopic characterisation of some manganese(II) complexes of triphenylphosphine of unusual stoicheiometry, Mn(PPh3)X2

Abstract Novel manganese(II) complexes of triphenylphosphine, Mn(PPh 3 )X 2 (X = Cl, Br, I, NCS), have been isolated and studied by a number of spectroscopic techniques. The basic structure in the solid state is pseudotetrahedral and the complexes may be oligomeric. The Mn(OPPh 3 )(NCS) 2 complex, synthesised for comparative purposes, differs from Mn(PPh 3 )(NCS) 2 in a number of important ways.

The reaction of coarse-grain metal powders with phosphoranes: a facile activation of metallic reagents and a novel route to metal–phosphine complexes. The X-ray crystal structures of Mnl2(PPhMe2) and FeBr3(PPhMe2)2

A route to new and existing transition metal phosphine complexes is provided by the reaction of coarse-grain metal powders and phosphoranes in diethyl ether, as exemplified here by Nil3(PMe3)2, FeBr3(PPhMe2)2 and Mnl2(PPhMe2).

Diiodophosphoranes. Synthesis and structure in the solid state and in solution

Nineteen diiodophosphoranes, R3PI2(R3= Ph3, substituted triaryl, mixed arylalkyl, or trialkyl), the vast majority of which have previously not been reported, are described. Their 31P{H} NMR data indicate an ionic [R3PI]I structure in CDCl3 solution, in keeping with results of other solution studies of a limited number of dihalogenophosphoranes, but solid-state 31P-{H} magic angle spinning NMR data for R3PI2(R3= Ph3, PhMe2 or Me3) indicate a molecular four-co-ordinate R3P–I–I structure, strongly suggesting that this is the common structure for diiodophosphoranes, and not the five-co-ordinate trigonalbipyramidal structure of conventional wisdom.

The coordination of small molecules by manganese(II) phosphine complexes. Part 13. The synthesis and characterisation of some novel manganese(II) complexes of tertiary butylisocyanide, MnX2(CNBut) (X = Cl, Br, I, NCS), and their reaction with tri(n-butyl)phosphine and molecular oxygen

Abstract Novel tertiary butylisocyanide complexes of manganese(II) with unusual stoichiometry, MnX2(CNBut) (X = Cl, Br, I, NCS), have been prepared and characterised by magnetic susceptibility measurements and infrared and electron spin resonance spectroscopy. For X = Cl, Br, I the complexes have been assigned a polymeric structure similar to that found for MnI2(PPhMe2), whilst Mn(NCS)2(CNBut) is probably dimeric as the infrared spectrum exhibits bands assignable to both bridging and terminal thiocyanate groups. The MnX2(CNBut) show no ability to reversibly bind dioxygen, but in solution in tetrahydrofuran PBu3n displaces the isocyanide ligand and for X = Cl, Br, I these solutions absorb dioxygen in a 1:1 Mn:O2 ratio.

Crystal structures of trinuclear [{MnI2(PPhMe2)1.33}3] and tetranuclear [Mn4(µ4-O)I6(PPhMe2)4] formed by OO bond cleavage by the former

The unique trinuclear complex [{MnI2(PPhMe2)1.33}3] has been prepared and its crystal structure determined. It consists of a pseudo-octahedral MnI4P2 unit sandwiched by two pseudo-tetrahedral MnI3P units held together by bridging iodines. Under controlled conditions this complex cleaves dioxygen to produce the tetranuclear complex [Mn4(µ4-O)I6(PPhMe2)4], the structure of which has also been determined.

The reaction of cobalt powder with tetraiodo {1,2-bis(dibenzylphosphino)ethane} to form 1,2-bis (dibenzylphosphino)ethane cobalt diiodide, Co(dBzP2)I2; and the X-ray crystal structure of the diphosphinodioxide complex, Co{dBzP2(O)2}I2

Abstract The interaction of 1,2-bis(dibenzylphosphino)ethane, (dBzP 2 ) with diiodine in a 1:2 molar ratio leads to the isolation of tetraido {1,2-bis(dibenzylphosphino)ethane}, (dBzP 2 I 4 ) which readily reacts with coarse-grain cobalt powder to yield sky blue 1,2-bis(dibenzylphosphino)ethane cobalt diiodide, Co(dBzP 2 )I 2 . Exposure of a diethyl ether solution of Co(dBzP 2 )I 2 to air yields crystals of 1,2-bis(dibenzylphosphino)ethane cobalt diiodide. Co{dBzP 2 }I 2 . Exposure of a diethyl ether solution of Co(dBzP 2 )I 2 to air yields crystals of 1,2-bis(dibenzylphosphinoyl)ethane cobalt diiodide. Co(dBzP 2 (O) 2 }I 2 . The X-ray crystal structure of Co{dBzP 2 (O) 2 }I 2 reveals an infinite ribbon of the diphosphinedioxide-bridged cobalt(II) complex.

PREPARATION AND CRYSTAL STRUCTURE OF MANGANESE(II) ISOTHIOCYANATE TETRAHYDRATE

Crystals of Mn(NCS) 2 ·4H 2 O were isolated from an aqueous solution obtained by mixing solutions of barium thiocyanate and manganese(II) sulphate tetrahydrate. The crystals are monoclinic with a = 7.827(7), b = 9.208(1), c = 7.456(5) A, β = 112.57(5)°, space group P2 1 /c. The structure consists of discrete centrosymmetric trans -[Mn(NCS) 2 (H 2 O) 4 ] octahedra linked by hydrogen bonds.

The reaction of coarse-grain manganese powder with diiodotrimethylphosphorane to form [Mn(PMe3)I2]n, which reacts with trace quantities of molecular oxygen to form the mixed (+2/+3) oxidation state complex [Mn2(PMe3)3I5]PMe3

Coarse-grain unactivated manganese powder reacts with Me3Pl2 in diethyl ether to form the polymeric [Mn(PMe3)I2]n complex, I, which reacts with trace quantities of dioxygen to form dinuclear [Mn2(PMe3)3I5]·PMe3, II, the first mixed oxidation state (+2/+3) manganese complex which contains phosphine ligands; both I and II react with an excess of dioxygen to form the monomeric [Mn(PMe3)2I3].