Ruthenium dithiophosphates: synthesis, X-ray crystal structure, spectroscopic and electrochemical properties

Abstract

The reactions of ammonium salts of dialkyldithiophosphate ligands, (RO) 2 PS 2 y NH 4 q (RsMe/Et), with Ru III Cl 3 P3H 2 O in methanol solvent and under N 2 atmosphere result in one-electron paramagnetic tris complexes {(RO) 2 PS 2 } 3 Ru III (1) in the solid state. The molecular structures of both complexes were determined by single-crystal X-ray diffraction. This shows the expected pseudo-octahedral geometry with reasonable strain due to the presence of a four-membered chelate ring. The reflectance spectra of the solid complexes display two bands in the range 596-476 nm and in the solid state the complexes exhibit one isotropic EPR signal at 77 K. Although the complexes 1 are stable in the solid state, in solution the complexes are transformed selectively into the diamagnetic and electrically non-conducting sulfur-bridged dimetallic species [{(RO) 2 PS 2 } 2 Ru IV (m-S) 2 Ru IV {S 2 P(OR) 2 } 2 ]. The formation of dimeric species in the solution state is authenticated by the electrospray mass spectrum of one representative complex where RsEt (1b). In dichloromethane solution the complexes show two moderately strong sulfur to ruthenium charge-transfer transitions in the range 514-419 nm, and two strong ligand based transitions in the UV region. The complexes exhibit two successive reversible reductions in the ranges 1.01™0.91 V and y0.44™y0.49 V versus SCE corresponding to Ru IV -Ru IV /Ru III -Ru III and Ru III -Ru III /Ru II -Ru II couples respectively. Electrochemically or chemically generated first step reduced complexes [{(RO) 2 PS 2 } 2 Ru III (m-S) 2 Ru III {S 2 P(OR) 2 } 2 ] 2y display two ligand to metal charge-transfer transitions in the visible region and in the complexes the two one-electron paramagnetic metal centers (low-spin Ru III , ,Ss1/2)are antiferromagnetically coupled. t 2gThe second step reduced species [{(RO) 2 PS 2 } 2 Ru II (m-S) 2 Ru II {S 2 P(OR) 2 } 2 ] 4y are observed to be very unstable.

Tris(diisopropyl dithiophosphato-κ2S,S′)ruthenium(III)

“…Each four-membered RuS 2 P ring is nonplanar and contains a pair of nearly equal Ru-S bonds (Table 1) (Liu et al, 2005). The bond distances within the di-iso-proposaldithiophosphate ligands of the title complex agree well with those found in the analogous dimethyl-and diethyldithiophosphate complexes of ruthenium (Jain et al, 2000).…”

Metal-centered oxidation decreases nitrile hydration activity of bioinspired (N2S3)Ru-PPh3 precatalysts

“…The X-band EPR spectrum of 4 exhibits an isotropic signal with g = 2.088 with weak coupling to the I = 5/2 nuclear spin of 99,101Ru (29.8%) confirming an S = 1/2 spin-state,Figure 1 [19]. Lahiri and coworkers observed a similar isotropic EPR spectrum for a low spin Ru(III) complex with dialkylthiophosphate donors [20].…”

The space group of tris(dimethyldithiophosphato)ruthenium(III)

“…metal-organic papers ORTEPII (Johnson, 1976) plot of the title compound with ellipsoids at the 50% probability level. The crystal structure of tris(dimethyldithiophosphato)ruthenium(III), (I), was originally described in the Cc space group (Jain et al, 2000). A check for additional symmetry by using the program PLATON (Spek, 1990) indicated that the correct space group for this structure is C2/c.…”