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The preparation and properties of a new type of partially oxidised tetracyanoplatinate salt, Pb0.77K0.23[Pt(CN)4]·1.5H2O, are reported. The electrical conduction properties are compared with those of previously known one-dimensional metallic complexes of platinum.

The d.c. conduction properties of (NH4)2Pt-(CN)4Cl0.3·3.2H2O and (NH4)2.2Pt(CN)4Cl0.5·3.OH2O are compared with those of K2Pt(CN)4Br0.3·3.2H2O and the unique role of NH4+ ions in this type of compound is described.

The X-ray crystal structure analysis of Li0.75[Pt(mnt)2]·2H2O (mnt = 1,2-dicyanovinylene-1,2-dithiolato,C4N2S22–) has revealed that the planar [Pt(mnt)2]n– anions stack face-to-face along the c-axis with an eclipsed structure and with a Pt ⋯ Pt distance of 3.639 A, which indicates that the conduction pathway is different from that in either the coducting organic salts of tetracyanoquinodimethane or the partially oxidised platinum-atom chain compounds.

A series of new one-dimensional metals based on partially oxidised tetracyanoplatinate complexes containing both monovalent and divalent cations is described. The complexes appear to be isostructural with K2[Pt(CN)4]Cl0.3·3H2O but with ca. 13% of the cation sites containing a divalent cation and with all the halide sites occupied. The small change in composition is shown to have a large effect on the electrical conduction properties of the compounds because the effect of the introduction of divalent cations results in an increased stiffness of the lattice. This leads to a reduction of λ, the electron phonon coupling constant, resulting in increased conductivity at low temperatures.

An open-ended project in which students work in small groups devise the best methods for analyzing aqueous wastes.

The preparation and properties of a series of partially oxidised bis(oxalato)platinate salts of ammonium and methyl-substituted ammonium cations are described. Their electrical conduction properties are related to the value of the Fermi wave-vector determined from X-ray diffuse scattering experiments and the presence of three-dimensional superstructures at room temperature.

The preparations, electrical conductivities, magnetic and spectroscopic properties of bis[cis-1,2-bis(trifluoromethyl)-1,2-ethylenedithiolato]nickelate, [Ni{S2C2(CF3)2}2]–, and bis[cis-1,2-bis(trifluoromethyl)-1,2-ethylenediselenato]nickelate, [Ni{Se2C2(CF3)2}2]–, salts with small counter ions are described.

The preparation of two series of 3,7-bis(dimethylamino)phenothiazin-5-ium (methylene blue, mb) salts with [M{S2C2(CN)2}2]2– and [M{S2C2(CN)2}2]–(M = Ni, Pd, Pt, or Cu) is described. Compressed pellets of all these compounds exhibit conductivities of less than 10–5Ω–1 cm–1 at room temperature. Single crystals of [mb][Pt{S2C2(CN)2}2] behave as semiconductors with an activation energy of 238 meV and a room-temperature conductivity of 10–5Ω–1 cm–1.

U.v.–visible spectral studies show that in acetonitrile solution there is association between [Rh(CO)2(L–L)]+ or [Rh(CO)3(L–L)]+[where L–L = 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen)] cations and [RhX2(CO)2]–(where X = Cl or Br) anions. The extent of the interaction depends on L–L and X and is most pronounced for [Rh(CO)3(phen)]+ and [RhCl2(CO)2]–. The anion–cation compound formed by the reaction of L–L with [(OC)2Rh(µ-Cl)2Rh(CO)2] has been shown to be [Rh(CO)3(L–L)][RhCl2(CO)2]. All four compounds of the type [Rh(CO)3(L–L)][RhX2(CO)2] have been prepared in crystalline form by the action of CO on a solution of [Rh(cod)(L–L)][BPh4](cod = cyclo-octa-1,5-diene) and [RhX2(CO)2]– in 1,2-dichlorobenzene, a new preparative method.

In contrast to previously studied molecular metal conductors based on metal complex anions, studies of the variation with temperature of the conductivity of K0.4[Ni(dmit)2] show no metal to semiconductor transition down to 20 K.

The preparation, optical, and electrical conductivities of nickel, palladium, and platinum complexes of S2C2R22– ligands (where R = CN, Me, Ph, or H) are described together with attempts to produce new one-dimensional metals based on these metal complexes.