Systematic structural control of multichromic platinum(ii)-diimine complexes ranging from ionic solid to coordination polymer

Abstract

Reactions of a Pt(II)-diimine-based metalloligand Na 2 [Pt(CN) 2 (4,4'-dcbpy)] (4,4'-H 2 dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) with alkaline-earth metal salts Mg (NO 3 exhibit any chromic behaviour. Combination analysis of powder X-ray diffraction, thermogravimetry, and IR spectroscopy suggests that the dimensionality of the coordination network contributes considerably to both the structural flexibility and luminescence properties; that is, the low-dimensional flexible coordination network formed in MPt-4 complexes with smaller alkaline-earth metal ions enables a structural rearrangement induced by thermal and mechanical stimuli and vapour adsorption, resulting in 25 the observed multichromic behaviour.

Visualization of Ion Conductivity: Vapochromic Luminescence of an Ion-Conductive Ruthenium(II) Metalloligand-Based Porous Coordination Polymer

“…6 We also reported on the solid-state solvatochromic behavior of the coordination polymer (CP) composed of a phosphorescent platinum(II) metalloligand with alkaline-earth metal ions. 7,8 These luminescent sensing materials are useful for visualizing the existence of harmful chemical vapors by changes in their luminescence. 9−12 On the other hand, only a few materials show luminescence associated with the change of a macroscopic phenomenon like ion conduction.…”

Powder Structure Analysis of Vapochromic Quinolone Antibacterial Agent Crystals

“…In the PPA trihydrate phase, the NH 2 + forms hydrogen bonds with O COO-atoms in the same layer and the adjacent layer (Figure 16c). Interestingly, R 4 4 (12) hydrogen bond motif shown in ENX anhydrous phase also exists in PPA trihydrate, but not in ENX trihydrate phase. After the dehydration transformation, in the PPA anhydrous A and B phase, there are no hydrogen bond acceptors for the assumed NH 2 + moiety (Figure 16d,e).…”

“…Most reported vapochromic materials are crystals of transition metal-containing complexes. The vapochromism mechanisms in metal complex crystals are classified into three types: vapochromism by desolvation−solvation, 11 by solvent exchange, 12 and by a change in the coordination environment owing to solvent molecule ligation (chemical reaction). 13−15 In general, the color of metal complexes is sensitive to changes in the coordination environment and can easily be altered due to variations in the d−d transition energy.…”

“…Most reported vapochromic materials are crystals of transition metal-containing complexes. The vapochromism mechanisms in metal complex crystals are classified into three types: vapochromism by desolvation–solvation, by solvent exchange, and by a change in the coordination environment owing to solvent molecule ligation (chemical reaction). − In general, the color of metal complexes is sensitive to changes in the coordination environment and can easily be altered due to variations in the d–d transition energy. Thus, small changes in the crystal environment upon exposure to vapor can lead to a vapochromic color change in metal complex crystals.…”

Proton-switchable vapochromic behaviour of a platinum(ii)–carboxy-terpyridine complex

“…Especially, vapochromic materials that exhibit reversible colour change in response to harmful volatile organic chemical (VOC) vapours have been extensively studied for use in chemical sensors to detect such harmful chemicals in our environment. [1][2][3][4][5] The colour and luminescence of square-planar Pt(II) complexes strongly depend on their stacking orientation in the solid state, which directly affects the intermolecular metallophilic interactions between adjacent Pt(II) ions (i.e., modifies the metal-metal-to-ligand charge transfer (MMLCT) transition); [6][7][8] therefore, many vapochromic complexes, including simple neutral mononuclear complexes, [9][10][11][12][13][14][15][16][17][18][19][20] ionic complexes, [21][22][23][24][25][26][27][28][29][30] double salts, [31][32][33][34] dinuclear complexes, [35][36][37][38] and coordination polymers, [39][40][41] have been reported. Most of the vapochromism of Pt(II) complexes reported to date originates from reversible structural transformations induced by vapour adsorption/desorption, which changes the molecular stacking in the solid state.…”