Structural and photophysical properties of luminescent cyanometallates [M(diimine)(CN)4]2− and their supramolecular assemblies

Abstract

Luminescent complexes of the [M(diimine)(CN)(4)](2-) family (M = Ru, Os), and their polynuclear analogues, are structurally versatile components for preparation of supramolecular assemblies based on interaction of the cyanide groups with other metal ions or metal complexes via direct coordination, hydrogen bonding, or halogen bonding. In addition their environment-dependent photophysical properties (solvatochromism and metallochromism), and the ability of the CN groups to act as reporters for excited state behaviour via time-resolved IR spectroscopy, make these fragments spectroscopically as well as structurally versatile. This Perspective article summarises work from the author's group over the last decade on the structures and photophysical properties of these fascinating complexes and their supramolecular assemblies.

Structures, Electrochemical and Spectral Properties of a Series of [MnN(CN)3(diimine)]– Complexes

“…[16,17] ) anions have traditionally been used; [18,19] however, the development of [M(diimine) (CN ) complexes has also afforded an extensive database of building blocks with the potential to act as tri-and tetradentate metalloligands. [1,3,4,20,21] This paper describes the synthesis and characterisation of a series of new cyanidometallates, [PPh 4 ][MnN(CN) 3 (diimine)] {diimine = 2,2Ј-bipyridine [1(bpy)], 4,4Ј-dimethyl-2,2Ј-bipyridine [1(4-dmbpy)], 5,5Ј-dimethyl-2,2Ј-bipyridine [1(5-dmbpy)], 1,10-phenanthroline [1(phen)] and bipyrimidine [1(bpym)]}. This series allows for a fundamental study of the impact of ligand substitution on the properties of the metal centre and enables the rationalisation of the influence of the π-accepting nature of the diimine ligand on the electrochemical and spectral properties of the metal complex.…”

“…[1][2][3][4][5][6][7] These features are based on the direct coordination of metal species with the uncoordinated N-termini of the cyanido ligand or solvent-mediated hydrogen-bonding interactions as well as outer-sphere solvent effects. [8,9] Materials displaying these properties have been researched intensively for their potential applications in chemical sensing, as chromophores in dye-sensitised solar cells, [10,11] and for their electrochemical properties.…”

Luminescent Cyanoruthenate(II)Diimine and Cyanoruthenium(II)Diimine Complexes

“…In addition to their unique bonding features, the lone‐pair of electrons on the nitrogen atoms of the cyanide ligands, which can interact with solvent molecules or electron acceptors, also gives rise to highly environmentally sensitive photophysical properties in luminescent cyanometalates 2b. f, 3 These properties have been extensively studied in the most‐popular cyanoruthenate system, that is, [Ru(CN) 4 ($\widehat{NN}$ )] 2− ,2f, 3a–g and they have been found to be useful in the development of luminescent chemosensors, probes, and stimuli‐responsive devices 2g. 4 Although luminescent cyanometalates possess many intriguing and favorable properties, modification of their properties is challenging when the only modifiable diimine ligand is functionalized for various applications.…”

“…4 Although luminescent cyanometalates possess many intriguing and favorable properties, modification of their properties is challenging when the only modifiable diimine ligand is functionalized for various applications. Moreover, the luminescent quantum yields and emission lifetimes of most of these cyanometalates are very low,2f, 3 thereby limiting the performance of their applications. Replacing the metal center is one possible strategy for tuning the properties of cyanometalates and does not require the redesign of the functionalized diimine ligand 2f.…”

“…Moreover, the luminescent quantum yields and emission lifetimes of most of these cyanometalates are very low,2f, 3 thereby limiting the performance of their applications. Replacing the metal center is one possible strategy for tuning the properties of cyanometalates and does not require the redesign of the functionalized diimine ligand 2f. 3g, h, i In this context, we recently developed a new family of cyanorhenatediimine complexes 3i.…”