Hydrogen-bonded assemblies of ruthenium(ii)-biimidazole complex cations and cyanometallate anions: structures and photophysics

Abstract

The complex cations [RuL2(H2biim)]2+ (L=bipy, 4,4'-tBu2-bipy) interact with cyanometallate anions via a chelating hydrogen-bonding interaction between the two N-H donors of the complex cation and the N lone pair of one cyanide ligand in the complex anion; the anion hexacyanoferrate(III) quenches the Ru(II)-based luminescence in CH2Cl2 solution by photoinduced electron-transfer within the H-bonded assembly, whereas hexacyanocobaltate(III) enhances the Ru(II)-based luminescence.

fac-Acetato-bis(pyrazole) complexes: A systematic study on intra- and intermolecular hydrogen bonds

“…Both structures present the usual pseudooctahedral geometry of (g 3 -methallyl)molybdenum complexes, with the open face of the allyl moiety oriented over the carbonyls. As evidenced by Table 2, the distances and angles are very similar in both complexes, and 80.03 (8) 80.6(4) C(2)-Mo(1)-Cl (1) 97.03 (9) 102.9(5) C(1)-Mo(1)-Cl (1) 167.98 (9) 173.3(6) N(1)-Mo(1)-Cl (1) 84.05 (6) 79.1(4) N(3)-Mo(1)-Cl (1) 81.31 (6) 78.2 (4) similar to those described above for 1a and 1b or for the previously reported structures of bis(pyrazole)halodicarbonylmolybdenum(II) complexes [10b,15]. As occur in these structures, one of the pyrazole ligands is coordinated trans to the allyl group.…”

“…This is one of the big challenges of chemistry, that is, the understanding and control of the organization of molecules [4]. Hydrogen bonded organic aggregates have so far been object of main attention, but the presence of metals in supramolecular systems is attracting increasing interest, as they may show redox [5], optical [6], magnetic [7], adsorption [8], or catalytical [9] properties. We considered that complexes containing the fac-''MX(pz * H) 2 " (X = halogen, pz * H = any pyrazole) moiety [10] could be good precursors to start this study, if the halogen is replaced by another ligand able to establish hydrogen bonding interactions with the hydrogens of pyrazoles.…”

Dendrimer-like cyanoruthenate anions with high potential connectivity derived from a [Ru(bpym)3]2+ core

“…This allows the direction of energy-transfer between the components of dyads containing a [Ru(diimine)(CN) 4 ] 2− unit to be reversed simply by changing the solvent composition [4] or adding metal salts [3]. In addition the cyanide lone pairs provide numerous means of incorporating [Ru(diimine)(CN) 4 ] 2− units into supramolecular assemblies, such as hydrogen-bonding [5], halogen-bonding [6], and formation of dative bonds to other metal ions to give polynuclear assemblies based on Ru-CN-M bridges [3,7]. The IR activity of the cyanide groups provides a valuable spectroscopic handle for studying the excited state properties and dynamics of complexes containing [Ru(diimine)(CN) 4 ] 2− units via the technique of time-resolved infrared spectroscopy [4c,8].…”

Crystal structure of bis(biimidazole-k2N,N')bis(perchlorato-kO)copper(II) - N,N-dimethylformamide (1:1), Cu(C6H6N4)2(ClO4)2 · C3H7NO

“…The consideration and utilization of the coordination bonds of atransition metal ion, intermolecular hydrogen bonds and p-p packing interactions also help to control the molecular arrangement [1][2][3][4] The hydrogen bonding is regarded as robust power in the construction of supramolecular polymers. It also provides useful information to understand the complicated processes in biological systems [5][6][7] …”