Hydrogen bonding interactions in single component molecular conductors based on metal (Ni, Au) bis(dithiolene) complexes

Abstract

Nickel (closed-shell) or gold (radical) bis(dithiolene) neutral complexes, functionalized with hydroxyethyl and thiazole moieties, afford hydrogen-bonded single component conductors.

C–H⋯NC hydrogen bonding in cyanobenzene-ethylenedithio-tetrathiafulvalene compounds

“…This type of R 2 2 (10) synthon mediated by H α -bond acceptor interactions was observed in compounds (4-CNB-EDT-TTF)I 3 (5), (4-CNB-EDT-TTF)ClO 4 ( 6), (4-CNB-EDT-TTF)BF 4 (7), (5-CNB-EDT-TTF)FeBr 4 , ( 15), (5-CNB-EDT-TTF) 2 Cu 2 Cl 6 (16), and (5-CNB-EDT-TTF) 2 Hg 2 Br 6 (17). However, this synthon is rarely observed isolated and, as shown in Fig.…”

“…1 In this context, non-covalent interactions such as hydrogen and halogen bonds are valuable crystal engineering tools that have played a major role in the development of molecular conductors. This was the case for hydrogen bonds in amide-functionalised TTF derivatives [2][3][4] and for the more recent partial oxidation and metallic behaviour induced by hydrogen bonds in TTF-catechol derivatives (H 2 Cat-EDT-TTF), 5,6 some transition metal bisdithiolene complexes as single component conductors, 7 and the controlled redox properties and structure in TTF-imidazole salts. 8 Weaker intermolecular interactions such as those of halogens 9,10 and chalcogens 11 have been also relevant for the structural control of different molecular conducting materials.…”

The quest for single component molecular metals within neutral transition metal complexes

“…Another family with thiazole rings worth mentioning is the series [M(RS-tzdt) 2 ] (RS-tzdt: 2-alkyl-thio-1,3-thiazole-4,5dithiolate; M: Au 80 and Ni; 81 R: Et, Me and EtOH, 82 Chart 3). Regarding [Au(RS-tzdt) 2 ] with Me and Et substituents both revealed a semiconducting behaviour with a s RT of 8 Â 10 À3 S cm À1 (E a = 0.13 eV) and 3.3 Â 10 À4 S cm À1 (E a = 0.12 eV), respectively.…”

“…The hydrogen bonds control the overall crystal structures regardless of their different open/closed shell nature. 82 The nickel complex behaves as a band semiconductor with a weak s RT (1.6 Â 10 À5 S cm À1 ), while the gold complex is described as a Mott insulator with a s RT three orders of magnitude higher (0.06 S cm À1 ).…”

Modulation of the electronic states and magnetic properties of nickel catecholdithiolene complex by oxidation-coupled deprotonation

“…For this purpose, H-bonding metal dithiolene complexes functionalized with hydroxy groups are suitable candidates as the building blocks of new electron-proton-coupled materials. [42][43][44][45][46] Metal dithiolene complexes are d/p-electronconjugated systems, which exhibit a wide range of electronic functionalities in solid states (magnetic/optical properties and electrical conductivity) owing to their multiple redox ability, widely delocalized frontier orbitals, and narrow HOMO-LUMO gap. [47][48][49][50][51][52][53] The multiple redox activity and widely delocalized frontier orbitals are advantageous for modulating their electronic state with H-bond formation and proton transfer.…”