D.H. Brown

The far infra-red spectra of some transition metal halide complexes with substituted pyridines

Far infra-red spectra (650-200 cm−1) have been recorded for a series of complexes in which substituted pyridines are co-ordinated to transition metal halides. The spectra are correlated with the known structures of the complexes.

The preparation and spectroscopic properties of some aniline complexes of transition metal halides

Abstract Aniline complexes of manganese (II), cobalt (II), nickel (II), zinc, and cadmium chlorides, bromides, and iodides and of copper (II) chloride and bromide have been prepared. Ultraviolet and visible reflectance spectra and far infrared spectra have been recorded for the solid complexes and the spectra are used to determine the probable co-ordination arrangement about the metal atoms in each complex.

The thermal decomposition of metal complexes—IV: The preparation and thermal decomposition of some pyridine and substituted-pyridine complexes of nickel (II) halides

Abstract Complexes have been prepared between pyridine, α-, β- and γ-picoline, 2,6-lutidine, and s -collidine and nickel (II) chloride, bromide, and iodide. The thermal decomposition of these complexes has been studied. Diffuse reflectance spectra have been measured for all complexes and have been used to determine the environment about the nickel atoms.

The thermal decomposition of metal complexes—V. The decomposition of some pyridine and substituted-pyridine complexes of manganese (II) halides

Abstract Complexes have been prepared between pyridine, α-, β-, and γ-picoline, 2,6-lutidine, and s-collidine and cobalt(II) chloride, bromide, and iodide. The thermal decomposition of these complexes has been studied. Complexes have been prepared between acridine and cobalt(II) bromide and iodide. Diffuse reflectance spectra have been measured for all complexes and have been used to determine the environment about the cobalt atoms.

Some metal halide complexes of morpholine-4-thiocarbonic acid anilide

Abstract Some metal(II) halide complexes of morpholine-4-thiocarbonic acid anilide have been prepared and characterized by analysis, conductance and spectroscopic techniques. The complexes are of the type MX 2 (ligand) 2 where M = cobalt(II), zinc(II), cadmium(II) and mercury(II) and X = chloride, bromide and iodide. The thermal decompositions of the complexes have been examined and shown to proceed through breaking of metal-sulphur bond. The corresponding N,N′-diphenyl thiourea complexes have also been prepared and the properties of the two sets of complexes compared.

Molybdenum(V) and (VI) complexes with some naturally occurring ligands

Abstract The formation of complexes is described between molybdenum(VI) and the ligands L-asparagine, L-aspartic acid, L-alanine, 2,3-diketo-L-glutonic acid and L-threonic acid and between molybdenum(V) and the ligands L-serine, L-aspartic acid, L-threonine, D-sorbitol, D-mannitol, L-arabitol and 2,3-diketo-L-gulonic acid. These complexes were identified by the formation of optically active species in solution.

The preparation, thermal decomposition, visible and infrared spectra of some chromium(III) halide complexes

Abstract A number of chromium(III) chloride and bromide complexes with pyridine, 3- and 4- picolines and bipyridyl have been prepared by precipitation from solution and by thermal decomposition techniques involving loss of volatile ligand from parent complexes. On the basis of analysis, visible reflectance and i.r. spectra, possible structures are discussed.

The preparation and far I.R. spectra of some indium trihalide complexes

Abstract A number of indium trihalide complexes of pyridine, substituted pyridines, pyridine N-oxide and substituted pyridine N-oxides have been prepared by precipitation from solution and by thermal decomposition of other complexes. On the basis of their far i.r. spectra possible structures are discussed.

Some molybdenum(V) complexes with α-hydroxycarboxylic acids

Abstract Molybdenum(V) forms complexes with the following α-hydroxycarboxylic acids- l -mandelic, l -lactic, d -tartaric, l -malic, d -glucosaccharic, d -glyceric, d -erythronic, l -threonic, d -ribonic, d -lyxonic, l -arabinonic, d -xylonic, d -allonic, d -gluconic, d -talonic, d -mannonic, l -rhamnonic, d -gulonic and d -galactonic acids. These compounds were identified by the formation of optically active species in solution with Cotton effects about 22·0, 25·0 and 32·0 kK. The complexes exist in the pH range 2·5–8·5 with the exceptions of l -mandelic, l -lactic and d -glyceric acids whose complexes only exist about pH3. d -Tartaric and l -malic acids also formed complexes in 2N acid solution.

Complexes of molybdenum(V) with some aldoses and ketoses

Abstract Molybdenum(V) forms complexes with all the sugars examined, viz. d -mannose, d -lyxose, l -rhamnose, d -ribose, l -sorbose, d -fructose, d -xylose, l -arabinose, d -galactose, d -glucose. The first six sugars give complexes which show well defined cotton effects at about 25 kK and 34 kK. The signs of these cotton effects appear to depend on the conformation of the pyranose ring which can give rise to three hydroxyl groups so placed that they can occupy three adjacent sites in an octahedral complex. The remaining four sugars cannot have three hydroxyl groups so placed and their complexes give rise to poorly defined optical rotary dispersion spectra.