Synthesis and molecular studies of half-sandwich arene ruthenium and Cp*Rh/Cp*Ir complexes containing (3-picolyl)thiourea derivatives as N,S-bidentate donor ligands

Abstract

Series of mononuclear complexes of arene Ru and Cp*Rh/Cp*Ir complexes containing (3-picolyl)thiourea derivative ligands, of general formulae [(g 6 -arene)Ru(L)Cl]Cl and [Cp*M(L)Cl]Cl {L = benzoyl(3-picoylyl)thiourea, arene = benzene (1); p-cymene (2) and M = Rh (3); Ir (4); L = 1,3-bis(3-picolyl)thiourea, arene = benzene (5); p-cymene (6) and M = Rh (7); Ir (8)}, have been synthesized and characterized by spectroscopic methods. X-ray crystallographic studies of complexes (2)-(5), (7), and (8) reveal a typical piano-stool geometry around the metal center with a six-membered metallacycle, in which L acts as an N,S-chelating ligand. Intramolecular N-HÁÁÁS, SÁÁÁO, and N-HÁÁÁN interactions are found to play a significant role in the molecular structures.

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).…”

“…When methyl group is at the para position of the pyridine ring such as in benzoyl (4‐picolyl) thiourea (L2) it acted as bidentate chelating ligand whereas when methyl group is at the ortho position of the pyridine ring as in benzoyl (6‐picolyl) thiourea (L3) it behaved as neutral monodentate ligand. Previously we have shown that when methyl group is at the meta position of the pyridine ring such as in benzoyl (3‐picolyl) thiourea it coordinated metal in a bidentate chelating manner . Complexes ( 4 , 5 and 6 ) also have the cationic species [(arene) M (L2)к 2 ( N,S ) Cl] [(arene) = p ‐cymene, M = Ru and Cp*, M = Rh and Ir] and counter anion chloride.…”

“…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 .…”

Synthesis, Structural and Biological Studies of Some Half‐Sandwich d6‐Metal Complexes with Pyrimidine‐Based Ligands

“…The bond distance of metal to the nitrogen atom in all the complexes is within the range, i. e., ∼ 2.088(3) to 2.198(5) Å (Table ). The complexes contain 2‐aminopyrimidine are showing M−N and M−Cl bond lengths longer than the complexes containing 2‐mercaptopyrimidine ligand which is identical to the earlier values reported in literature {[(arene/Cp*) 2 M 2 (μ‐L1)Cl 3 ] + where, L1=pyridine‐2‐carbaldehyde nicotinoyl‐hydrazone 2.152(6); [Cp*MLCl] + where, L=benzoyl(3‐picolyl)thiourea/1,3‐bis(3‐picolyl)thiourea 2.335(2)‐2.4027(11)} . The metal to chloride ion of complexes ( 1 , 2 ) is 2.3983(19) to 2.434(2) Å which is the normal distance in the metal chloride complexes .…”

Synthesis, structural and chemosensitivity studies of arene d6 metal complexes having N‐phenyl‐N´‐(pyridyl/pyrimidyl)thiourea derivatives

“…Since the choice of ligands plays a crucial role in determining the biological properties of the complexes we decided to substitute aryl group with pyridyl group and determine the coordination properties of pyridyl thiourea derivatives. Previous studies in this laboratory have reported some half‐sandwich arene ruthenium, rhodium and iridium complexes with pyridyl thiourea ligands and in this study, we report the synthesis, structural and cytotoxic activity against cancer and non‐cancer cell lines in vitro of p ‐cymene ruthenium, Cp* rhodium and Cp* iridium complexes containing thiourea derivatives. Ligands used in the present study are shown in Chart 1.…”