Synthesis, Spectroscopic and Molecular Studies of Half‐Sandwich η⁶‐Arene Ruthenium, Cp* Rhodium and Cp* Iridium Metal Complexes with Bidentate Ligands

Abstract

The bidentate ligand benzoyl(2-pyridyl)thiourea (L1) was prepared by reaction of benzoyl isothiocyanate with primary amine (2aminopyridine) but the reaction with secondary amine bis(2pyridyl)amine, yielded the unexpected product bis(2-pyridyl)benzoylamine (L2). Mononuclear complexes of the general formula [(η 6arene)Ru(L)Cl] + {where, L = L1, arene = benzene (1); p-cymene (2); L = L2, arene = benzene (5); p-cymene (6)} and [Cp*M(L)Cl] + {where, L = L1, M = Rh (3), Ir (4); L = L2, M = Rh (7), Ir (8)}, 715 respectively, were formed by reaction of the ligands L1 and L2 with precursor complexes [(η 6 -arene)Ru(μ-Cl)Cl] 2 and [Cp*M(μ-Cl)Cl] 2 (M = Rh, Ir). The cationic complexes were characterized by FT-IR, UV/Vis, and 1 H-NMR spectroscopy as well as mass spectrometry. Xray crystallographic studies of these complexes reveal piano-stool-like arrangements around the metal atoms with six-membered metallacycles in which L1 and L2 act as a N,S-and N,N' chelating ligands, respectively.fields and their metal complexes have been utilized for several decades and are widely employed in coordination chemistry, supramolecular chemistry and materials synthesis. [20][21][22][23][24][25] To the best of our knowledge there is no report available in the literature regarding reactions of arene ruthenium and Cp*Rh and Cp*Ir complexes with benzoyl-(2-pyridyl)thiourea/ bis(2-pyridyl)benzoylamine ligands. Herein, the syntheses of a series of new mononuclear half-sandwich complexes of arene Ru II , Cp*Rh III and Cp*Ir III with these bidentate ligands are reported. The ligands used in this study are shown in Scheme 1. Scheme 1. Ligands used in this study.

Neutral and cationic half‐sandwich arene d6 metal complexes containing pyridyl and pyrimidyl thiourea ligands with interesting bonding modes: Synthesis, structural and anti‐cancer studies

“…The M‐S bond lengths in neutral complexes are slightly longer than that of cationic complexes (Table S3). The M‐Cl bond lengths in these complexes shows no significant differences and was found to be in the range of 2.399–2.438 Å which are comparable with earlier reported complexes . The bond angle values S‐M‐Cl and Cl‐M‐Cl in neutral complexes ( 7 – 9 ) lay in the range of 87.7–95.5 ° (Table S3).…”

“…Substitution of alkyl or aryl group with various other substituents is expected to alter the coordination modes of these ligands. When the alkyl or aryl group is replaced by a pyridyl group the ligand acted as neutral bidentate ligand coordinating metal in a (N, S) mode . Transition metal complexes of various thiourea derived ligands have been evaluated for their anti‐bacterial, anti‐cancer and anti‐microbial activities .…”

Design, Synthesis, DNA/HSA Binding, and Cytotoxic Activity of Half-Sandwich Ru(II)-Arene Complexes Containing Triarylamine–Thiosemicarbazone Hybrids

“…In the spectra of L3 , L4 , 3 , 4 , 7 , and 8 , signals of cyclohexyl protons are found in the regions 4.30–3.89 and 2.04–1.23 ppm. New signals were observed in the region 5.50–4.97 ppm, which is due to the presence of p -cymene complexes 36 1–4 (Figure S6), whereas a signal at 5.56–5.54 ppm for complexes 5–8 (Figure S7) showed the presence of benzene ring. 37 In the 13 C spectra of ligands L1–L4 (Figure S5) and complexes 1–8 , thiocarbonyl (C=S) and imine (C=N) carbon signals appeared around 176.1–175.7 and 174.8–171.2 ppm, respectively.…”

Synthesis, characterization and chemosensitivity studies of half-sandwich ruthenium, rhodium and iridium complexes containing к and к aroylthiourea ligands

“…In recent years, we have reported many organometallic complexes including halfsandwich platinum group metal complexes containing thiourea ligands [32][33][34]. Recently we have also reported the synthesis of strained complexes of arene d 6 metals containing benzoylthiourea ligand [35].…”