Stabilization of Isolated Mixed-Valence Trimers in a Novel Nickel Dithiolene Complex with CF2 Substituents
- 29 March 2001
- journal article
- research article
- Published by American Chemical Society (ACS) in Inorganic Chemistry
- Vol. 40 (9) , 2083-2087
- https://doi.org/10.1021/ic0013835
Abstract
The preparation of the novel paramagnetic nickel dithiolene complex Ni(F2pdt)2-• (F2pdt2-: 2,2-difluoro-1,3-propanediyldithioethylene-1,2-dithiolate) and its X-ray crystal structure as n-Bu4N+ salt are described. (n-Bu4N)[Ni(F2pdt)2] (2) crystallizes in the orthorhombic system, space group Pna21 with a = 21.379(4) Å, b = 8.9702(18) Å, and c = 18.527(4) Å. The radical anions are isolated from each other by the bulky n-Bu4N+ cations and exhibit a Curie-type magnetic behavior. Two reversible redox waves corresponding to the redox couples Ni(F2pdt)22-/-• and Ni(F2pdt)2-•/0 are observed at −0.55 and 0.30 V vs SCE, illustrating the electron withdrawing effect of the CF2 substituents. As a consequence, (TTF)3(BF4)2 oxidation of the radical anion does not afford the neutral Ni(F2pdt)20 but a TTF salt formulated as [TTF]3[Ni(F2pdt)2]3[CH2Cl2]. It crystallizes in the triclinic system, space group P1̄ with a = 12.330(3) Å, b = 12.726(3) Å, c =15.706(3) Å, α = 91.10(3), β = 110.78(3), and γ = 116.01(3). Donor and acceptor moieties are organized into (TTF)32+ and [Ni(F2pdt)2]32- trimers whose dicationic and dianionic charges have been inferred from the intramolecular bond lengths evolution and the singlet−triplet magnetic behavior. These trimers arrange orthogonally to each other into chess-board-like slabs, characterized by a segregation of the CF2 fragments and further stabilized by weak C−H···F interactions. Extended Hückel calculations show that only the nickel dithiolene complex trimer actually contributes to the magnetic susceptibility.Keywords
This publication has 34 references indexed in Scilit:
- Fluorinated Tetrathiafulvalenes with Preserved Electron-Donor Properties and Segregated Fluorous Bilayer Structures Based on F···F Nonbonded InteractionsThe Journal of Organic Chemistry, 2000
- Directing the Structures and Collective Electronic Properties of Organic Conductors: The Interplay of π-Overlap Interactions and Hydrogen BondsChemistry – A European Journal, 1999
- Cyano-halogen interactions and their role in the crystal structures of the 4-halobenzonitrilesJournal of the American Chemical Society, 1989
- On the band electronic structure of X [M (dmit)2]2 (X = TTF, (CH3)4N ; M = Ni, Pd) molecular conductors and superconductorsJournal de Physique, 1989
- Crystal and molecular structure of bis(tetrathiafulvalene) bis(maleonitrile-1,2-dithiolato)nickelate(II)Journal of Chemical Crystallography, 1986
- New Multi-Sulfur 1,2-Dithiolene Complexes. Preparation, Structure, and Electrochemical PropertiesBulletin of the Chemical Society of Japan, 1986
- Preparation and properties of tetrathiafulvalene (ttf) and tetramethyltetraselenafulvalene salts of tin(IV) halide anions and X-ray crystal structure of [ttf]3[SnCl6]J. Chem. Soc., Dalton Trans., 1984
- Tetrathiafulvalinium bis-cis-(1,2-perfluoromethylethylene-1,2-dithiolato)platinumActa Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 1976
- New approach to the preparation of tetrathiafulvalenium saltsJournal of the American Chemical Society, 1975
- Crystal structure of bis(tetrathiafulvalene)bis(diethiolene)nickelJournal of the American Chemical Society, 1975