Enhanced Anion Binding from Unusual Coordination Modes of Bis(thiourea) Ligands in Platinum Group Metal Complexes

Abstract

Treatment of a range of bis(thiourea) ligands with inert organometallic transition-metal ions gives a number of novel complexes that exhibit unusual ligand binding modes and significantly enhanced anion binding ability. The ruthenium(II) complex [Ru(η(6)-p-cymene)(κS,S',N-L(3)-H)](+) (2b) possesses juxtaposed four- and seven-membered chelate rings and binds anions as both 1:1 and 2:1 host guest complexes. The pyridyl bis(thiourea) complex [Ru(η(6)-p-cymeme)(κS,S',N(py)-L(4))](2+) (4) binds anions in both 1:1 and 1:2 species, whereas the free ligand is ineffective because of intramolecular NH⋅⋅⋅N hydrogen bonding. Novel palladium(II) complexes with nine- and ten-membered chelate rings are also reported.

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

“…Further the C‐S bond distances in these complexes was found to be in the range of 1.686‐1.700 Å suggesting that it is intermediate between single C‐S (1.82 Å) and double C=S (1.56 Å) bond distances . The bond lengths in these complexes are normal and consistent with the к 2 ‐N,S‐ coordination of the thiourea derivatives which correlates well with reported values for similar complexes . The metal to nitrogen bond distances is comparatively shorter than the metal to sulfur bond distances (Table ).…”

“…The metal to nitrogen bond distances is comparatively shorter than the metal to sulfur bond distances (Table ). The M‐Cl bond lengths in these complexes shows no significant differences and was found to be in the range of 2.39‐2.40 Å which is comparable to reported literature values . With respect to the bond angle values N(1)‐M(1)‐S(1), N(1)‐M(1)‐Cl(1), S(1)‐M(1)‐Cl(1) these are close to 90° suggesting pseudo‐octahedral geometry around the metal center (Table ).…”

Characterization of the anticancer effects of S115, a novel heteroaromatic thiosemicarbazone compound, in vitro and in vivo

“…There have been many reports on the synthesis, structure-activity relationship, and the anticancer effects of these compounds. Several complexes, including thiourea-platinum [18] , -gold [19] , -iron [20] , and -copper [21] , have been synthesized. Thiourea derivatives of classic anticancer drugs such as camptothecin [22] and podophyllum [23] have also been synthesized and tested for the anticancer activities.…”

Four Different Crystalline Products from One Reaction: Unexpected Diversity of Products of the CuCl2 Reaction with N-(2-Pyridyl)thiourea

“…Such coordination modes have been encountered especially in platinum group metal complexes. [16][17][18][19] The nitrogen-heterocyclic thiourea ligands are also efficient ligands for coordination to a Cu(I) cation producing a variety of monomeric and polymeric structures. 20,21 In addition, thioureas are widely recognized for their ability of hydrogen-bond formation and consequently supramolecular network arrangement.…”