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Your search keyword '"Coomber, A. Treeve"' showing total 7 results
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2. Structure and physical properties of the tetraphenylphosphonium-(Ni(dmit)2)3 (dmit = 2-thioxo-1,3-dithiol-4,5-dithiolate) salt

Author

Nakamura, Takayoshi, Underhill, Allan E., Coomber, A. Treeve, Friend, Richard H., Tajima, Hiroyuki, Kobayashi, Akiko, and Kobayashi, Hayao

Subjects
Complex compounds -- Analysis, Molecular structure -- Analysis, Organophosphorus compounds -- Analysis, Nickel compounds -- Analysis, Chemistry
Abstract

X-ray crystallographic study of tetraphenylphosphonium-Ni(dmit)2 (dmit = 2-thioxo-1,3-dithiol-4,5-dithiolate) indicates a novel stacking type for Ni(dmit)2. The compound behaves like a semiconductor at lower temperatures, while at room temperature it exhibits a one-dimensional conductivity. The magnetic susceptibility of the compound follows the Curie-Weiss law below room temperature, indicating localization of electron spin on the isolated Ni(dmit), while reflectance spectroscopy indicates no such localization.

Published
1995

6. Two tetrathiafulvalene salts of a new thiophene-functionalised ferracarborane: electrical conductivity as a function of crystal composition

Author

Yan, Yaw-Kai, Mingos, D. Michael P., Kurmoo, Mohamedally, Li, Wan-Sheung, Scowen, Ian J., McPartlin, Mary, Coomber, A. Treeve, Friend, Richard H., Yan, Yaw-Kai, Mingos, D. Michael P., Kurmoo, Mohamedally, Li, Wan-Sheung, Scowen, Ian J., McPartlin, Mary, Coomber, A. Treeve, and Friend, Richard H.

Abstract

Two tetrathiafulvalenium (TTF) salts of the new sandwich complex commo-3{,}3prime or minute]-Fe1-(thiophene-2-yl)-1,2-CBH], TTFFe(CBHCHS) and TTFFe(CBHCHS){,} are synthesized; while the 1 : 1 salt is an insulator{,} the 5 : 2 salt is a semiconductor featuring a conducting superlattice associated with a sublattice that shows ferromagnetic interactions between the ferracarborane complexes; single crystal X-ray studies of the 5 : 2 salt indicate that the electrical conductivity originates from a unique mixed-valence TTF network.

7. Synthesis, structure and physical properties of tetrathiafulvalenium salts of the ferracarborane complex commo-[3,3']-Fe1-(C4H3S)-{1,2-C2B9H10}2]

Author

Yan, Yaw-Kai, Mingos, D. Michael P., Kurmoo, Mohamedally, Li, Wan-Sheung, Scowen, Ian J., McPartlin, Mary, Coomber, A. Treeve, Friend, Richard H., Yan, Yaw-Kai, Mingos, D. Michael P., Kurmoo, Mohamedally, Li, Wan-Sheung, Scowen, Ian J., McPartlin, Mary, Coomber, A. Treeve, and Friend, Richard H.

Abstract

The sandwich complex -3{,}3prime or minute]-Fe1-(CHS)-1,2-CBH] and its tetrathiafulvalenium salts ttfFe(CBHCHS) and ttfFe(CBHCHS) were synthesised in order to study the effect of the thiophene (CHS) group on the crystal packing{,} electrical and magnetic properties of ttf-metallacarborane salts. The crystal structure of features unusual two-dimensional networks of ttf units which extend in the and directions. Each ttf sheet contains stacked trimers of ttf units{,} which propagate along the direction{,} and bridging ttf units{,} which lie between the ttf stacks approximately orthogonally to the ttf units within the trimers. The trimers are linked along the direction short S S contacts (3.56 A) with these bridging ttf units. In contrast{,} the crystal structure of compound contains discrete stacked dimers of ttfradical dot cations. Whilst crystals of are semiconducting (sigma= 2 times 10 S cm) with an activation energy of 0.22 eV{,} those of are insulating (sigmaless-than-or-eq 10 S cm). Both compounds exhibit weak ferromagnetic interactions between the unpaired spins of their Fe(CBHCHS) anions{,} with small positive Weiss constants of 1.9 and 0.5 K respectively.

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