Crystal structure of bis(triphenylphosphine)(carbonyl)(N-benzoyl-N'-(2-methyl-4-hydroxyphenyl)thioureato-κS,κN)rhodium(I), C52H43N2O3P2RhS

Abstract

Source of materialTo a cold DMF solution (5 mL) of [Rh(m-Cl)(CO) 2 ] 2 (30 mg, 0.1028 mmol) 2 equivalents of N-benzoyl-N'-(4-hydroxy-2-methylphenyl)thiourea were added [9]. After 4 minutes of stirring, ice-cold water was added to precipitate a dark-red solid. After isolating the solid, it was taken up in diethyl ether and treated with 4 equivalents of triphenylphosphine. The solvent was allowed to evaporate slowly, yielding the title compound as bright orange crystals. DiscussionIn our ongoing research in bidentate ligand systems, we have investigated the use of thiourea (tu) ligands for the synthesis of rhodium complexes, amongst others [1][2][3][4]. These ligands show exceptional coordination behaviour, being able to coordinate through their sulfur atom alone as a neutral monodentate ligand [5,6], through their sulfur and oxygen atoms as a monoanionic bidentate ligand [7], and as a monoanionic bidentate ligand through its sulfur and one of its nitrogen atoms (this work). This four-membered chelate ring has a very small bite angle of 63.06 (4)°, whereas the bite angle of the S,O-coordination mode is much closer to the preferred 90°for square planar coordination to rhodium(I) [8]. The coordination in the title compound can be described as distorted trigonal bipyrimidal, with the two triphenylphosphine ligands in the apical positions. Alternatively, the N,S-thioureato ligand can be considered as one donating moiety, in which case the complex can be described as distorted square planar. The rhodium-ligand bond lengths are all within expected ranges; the Rh-S and Rh-N bond lengths are 2.623(1) and 2.278(2) Å, respectively. The C-O bond length within the carbonyl ligand is 1.158(2) Å, while it is coordinated in an almost linear fashion, with a Rh1-C01-O1 angle of 176.9(2)°. The solid state structure is stabilized by both intra-and intermolecular hydrogen bonds. The intramolecular bond is between the N1 hydrogen and O2 (1.88(2) Å), whereas the intermolecular ones link two molecules together in a dimeric fashion from the phenolic hydrogen to the benzoyl oxygen (O2-H2···O3, 1.99 Å).

Acylchalcogenourea Complexes of Silver(I)

“…This N,S – coordination mode is extremely rare for acylthiourea derivatives. The rhodium(I) complex [Rh(CO){PhC(O)NC(S)NH(2‐Me‐4‐HOC 6 H 3 )(PPh 3 ) 2 }] reported by Warsink is the only other example of a metal complex with this coordination mode …”