Excited-State Distortions Determined from Structured Luminescence of Nitridorhenium(V) Complexes

Abstract

The nitridorhenium(V) complexes ReNCl(2)(PCy3)(2) (1), ReNBr(2)(PCy3)(2) (2), ReNCl(2)(PPh3)(2) (3), and ReNBr(2)(PPh3)(2) (4) produce structured emission spectra upon excitation at low temperature. The origin, E(00), occurs at 15 775, 16 375, 15 875, and 16 300 cm(-1), respectively. The vibronic peaks are regularly spaced with an average energy separation corresponding to the Re triple bond N stretching frequency. The nitridorhenium stretching frequency ranges from 1095 to 1101 cm(-1), as determined by Raman and IR spectroscopy. The excited-state distortions are calculated by fitting the emission spectra. The excited state arises primarily from a d(xy) (ReN nonbonding) to d(yz) (ReN pi antibonding) transition. The rhenium-nitrogen bond length in the excited state is 0.08 A longer than in the ground electronic state, which is consistent with the difference in bond lengths of ReN bonds of bond order 3 and bond order 2.5 as determined from molecular structures.

Synthesis, Structures, and Photoluminescent Properties of Tricyanidonitridorhenium(V) Complexes with Bipyridine-Type Ligands

“…This emission spectral feature is very similar to that of [Ru­(bpy derivative) 3 ] 2+ with the 3 MLCT excited state . The emission spectral shapes at 80 K are different from those of the complexes with the 3 [(d xy ) 1 (d π *) 1 ] (d π * = d xz and d yz with an admixture of the p orbital of the nitrido) excited state, which is usually observed in photoluminescent nitridorhenium­(V) complexes. ,, The emission spectrum of Re-(NH 2 ) 2 bpy in the crystalline phase has a shoulder band at a shorter wavelength than the emission maximum. At 80 K, Re-(NH 2 ) 2 bpy clearly shows peaks at 580, 619, and 660 nm.…”

Guest-Tunable Excited States in a Cyanide-Bridged Luminescent Coordination Polymer

“…This was supported by the emission spectra of CdRe, CdRe’, CdRe’_MeOH, and CdRe’_EtOH at 77 K (Figure S4). The resulting vibrational progression of the spectra is a characteristic of emission from the 3 [(d xy ) 1 (d π *) 1 ] (d π * = d xz , d yz ) state. ,− …”

13 Manganese, technetium and rhenium

“…47 The observation of emission spectra from the Re() nitride complexes [ReNX 2 (PR 3 ) 2 ] (X = Cl or Br; R = Ph or Cy) showed vibronic spacing corresponding to the Re-N stretching mode, with the Re-N bond extended by 8 pm in the excited state. 48 [ReOCl 3 (PPh 3 ) 2 ] reacts with 2-aminothiophenol (HL) to give [ReL 2 Cl(PPh 3 )]; corresponding Br and I (X) complexes were made from [ReOX 2 (OEt)(PPh 3 ) 2 ]. The chlorocomplex has trigonal prismatic structure, the first for bis(bidentate)bis(monodentate) complexes.…”