2,5-DisubstitutedN,N′-Dicyanobenzoquinonediimines (DCNQIs): Charge-Transfer Complexes and Radical-Anion Salts and Copper Salts with Ligand Alloys: Syntheses, Structures and Conductivities

摘要: The new members of the series 2,5-disubstituted DCNQIs, 1d (Cl/OMe), 1e (Br/OMe), 1j (Cl/I), 1k (Br/I), 1l (I/I), form conducting charge-transfer complexes with TTF (tetrathiofulvalene) which are comparable to known DCNQI/TTFs. From these DCNQIs highly radical-anion salts [2-X, 5-Y-DCNQI]2M (M = Li, Na, K, NH4, Tl, Rb, Ag, Cu) can also be prepared either from and MI (not AgI), on a metal wire (Ag, Cu), or by electrocrystallization Ag,Cu). For better crystals method using periodical switching between reduction partial oxidation has been developed. With CF3 (large, strongly electron-attracting) as substituent in 1m (OMe/CF3) 1n (Me/CF3), remain whereas only yields an insulating copper salt. DCNQI–Cu high conductivities obtained alloys containing two three different DCNQIs. temperature-dependent DCNQI–M (other than copper) similar those metal-like semiconductors. All metallic [M] down low temperatures, except [1d (Cl/OMe)]2Cu undergoes sharp phase transition state[M I]. By variation ligands their ratios tuned M I M. In addition, alloying produced for first time radical salt temperature-independent conductivity 5 300 K. Most remarkably, type [(2,5-Me2DCNQI)m] Cu/[{2,5-(CD3)2-DCNQI}n]2Cu exhibit further cooling reenter state transition, changes ca. 108 Scm−1 both ways. field organic metals crystal structures DCNQI–copper have determined X-ray powder diffraction methods refined Rietveld analysis. Unit cell data, coordination angles distances π planes excellent agreement single-crystal data. However, bond lengths less accurate. This proves most valuable if microcrystalline material is available.