Syntheses, electrochemistry, photophysics and photochemistry of nitridorhenium(V) diphosphine complexes and related nitridorhenium(V) organometallics; crystal structure of [Re^VN(CCBu^t)₂(PPh₃)₂]

Abstract

A series of nitrido complexes [ReNL,X]"+ [L = dppe(Ph,PCH,CH,PPh,), X = F, C1, Br, NCS, NCO or N, (n = 1) or MeCN (n = 2); L = dppbz(Ph,PC,H,PPh,-o), X = Cl (n = 1) or MeCN (n = 2)] have been synthesized and shown to exhibit long-lived photoluminescence in both the solid state and fluid solution, derived from the [(dXy)'(dx*)'] triplet (dx* = d,,, dyz). The positions of the d-d absorption and emission bands have been found to be dependent on the identity of X. The luminescence quantum yields of [ReNL,-(MeCN)], + are greatly enhanced with respect to their chloro analogues. Cyclic voltammetric studies show that the [ReNL,X] + complexes display an irreversible reduction couple at E,, of ca. -2.0 to -2.3 V and an irreversible oxidation couple at Epa of ca. + 1.3 to + 1.9 V us. the ferrocenium-ferrocene couple in MeCN

trans–cis Photoisomerization of the Styrylpyridine Ligand in [Re(CO)3(2,2′‐bipyridine)(t‐4‐styrylpyridine)]+: Role of the Metal‐to‐Ligand Charge‐Transfer Excited States

“…[6] The coordination to the metal center acts as a triplet photosensitization and the rate-determining step to reach the + was reported to be very low. [5] According to the mechanism depicted in Figure 7 this could be due to the presence of concurrent deactivation channels from the low-lying MLCT states to the electronic ground states. However there is no experimental evidence of such luminescent processes.…”

“…The photoizomerisation quantum yield determined for similar complexes with a NO 2 -substituted styrylpyridine ligand ranges between 0.47 and 0.66. [5] The ultrafast excitedstate dynamics of fac-[Re(Cl)(CO) 3 (t-4-styrylpyridine) 2 ] and fac-[Re(t-4-styrylpyridine)(CO) 3 …”

“…[3,4] A series of rhenium(i) diimine complexes with photoisomerizable pyridyl-azo, -ethenyl, or -ethyl ligands have been investigated for their photochemical, electrochemical, and photophysical properties. [5] The trans!cis photoisomerization of [Re(CO) 3 …”

A Highly Soluble Luminescent Decanuclear Gold(I) Complex with a Propeller-Shaped Structure

“…Structurally related gold(i) complexes with the general formulas [E(AuPPh 3 ) 3 ] (E S, Se, Te) and [E(AuPPh 3 ) 4 ] 2 (E S, Se) were also reported. [7] Here we report the synthesis and the structural characterization of a novel soluble, high-nuclearity luminescent m 3 -sulfidogold(i) complex with bridging diphosphanylamine ligands, namely, [Au 10 (m-PNP) 4 (m 3 -S) 4 ](PF 6 ) 2 (PNP Ph 2 PN(nPr)PPh 2 ).Reaction of H 2 S with a suspension of [Au 2 Cl 2 (PNP)] [9] in ethanol/pyridine followed by metathesis reaction with NH 4 PF 6 in methanol and recrystallization from acetone/ diethyl ether afforded [Au 10 (m-PNP) 4 (m 3 -S) 4 ](PF 6 ) 2 (1) as yellow crystals in 72 % yield. The formulation of 1 was confirmed by elemental analyses, positive FAB and ESI mass spectrometry, 1 H and 31 P NMR spectroscopy, 1 H ± 1 H COSY…”

“…Reaction of H 2 S with a suspension of [Au 2 Cl 2 (PNP)] [9] in ethanol/pyridine followed by metathesis reaction with NH 4 PF 6 in methanol and recrystallization from acetone/ diethyl ether afforded [Au 10 (m-PNP) 4 (m 3 -S) 4 ](PF 6 ) 2 (1) as yellow crystals in 72 % yield. The formulation of 1 was confirmed by elemental analyses, positive FAB and ESI mass spectrometry, 1 H and 31 P NMR spectroscopy, 1 H ± 1 H COSY experiments, and measurement of the molar conductivity.…”