Platinum(II) complexes of chelating and monodentate thiourea monoanions incorporating chiral, fluorescent or chromophoric groups

A comparative study of the metal binding behavior of alanine based bis-thiourea isomers

Two new symmetrical bis-thiourea, 2,2′-[{(terephthaloylbis(azanediyl)bis(carbonothioyl) bis(azanediyl)}dipropanoic acid] (1A) and 3,3′-[{(terephthaloylbis(azanediyl)bis (carbonothioyl)bis(azanediyl)} dipropanoic acid] (1B) were synthesized by the reaction of terephthaloyl chloride with α- and β-alanine in good yields. Their binding properties were investigated with various metal cations using UV–Vis titration experiments. Both isomers exhibited effective binding with Ag⁺, Cu²⁺, Hg²⁺, Pb²⁺, Fe²⁺ and Fe³⁺ cations. However, in the presence of other cations, such as Na⁺, Ni²⁺, Co²⁺, Cd²⁺, Zn²⁺, Mn²⁺, Mg²⁺, Ca²⁺, Sn²⁺, Al³⁺, and anions tetrabutylammonium Cl⁻ and H₂PO₄⁻, no interaction occurred. Both isomers displayed similar trends towards binding with metal cations.

Local structure of fluorescent platinum nanoclusters

Fluorescent nanoclusters synthesized from a variety of noble metals have recently been reported in the scientific literature. Various characterization methods have been employed in their study, but uncertainty still remains regarding the local structure of such materials. Herein we present the results of employing X-ray absorption spectroscopy to probe the local structure and electronic properties of platinum nanoclusters reduced and stabilized using N,N-dimethylformamide. Most notable amongst these results is an apparent lack of metallic bonding in the samples studied; in light of these findings, it is proposed that a non-metallic platinum nanocluster is instead responsible for the observed fluorescence behaviour.

1-[(Ferrocen-1-yl)meth-yl]-3-(naphthalen-1-yl)thio-urea

In the title compound, [Fe(C(5)H(5))(C(17)H(15)N(2)S)], the cyclo-penta-dienyl (Cp) rings are almost parallel and essentially eclipsed, with a dihedral angle between the Cp ring planes of 0.807 (11)°. The Fe atom is slightly closer to the substituted cyclo-penta-dienyl ring, with an Fe-centroid distance of 1.6510 (8) Å, compared with 1.6597 (8) Å for the unsubstituted ring. The bridging unit between the substituted Cp ring and the naphthyl ring system is planar within 0.0174 Å and makes dihedral angles of 59.032 (10) and 66.02 (2)°, respectively, with these two rings. The angle between the substituted Cp ring and the naphthyl ring system is 72.094 (18)°. The H atoms of the NH groups of the thio-urea moiety are positioned anti with respect to each other. In the crystal, mol-ecules form centrosymmetric dimers via pairs of N-H⋯S hydrogen bonds.

Normal coordinate analysis and crystal structure of N,N-dimethyl-N'-(2-chloro-benzoyl)thiourea

In the present paper, the crystal structural and vibrational analysis of the N,N-dimethyl-N'-(2-chloro-benzoyl)thiourea molecule is reported. The molecular structure of the title compound was determined by single crystal X-ray diffraction method. The compound crystallizes monoclinic, space group P2(1)/c with a=5.6601(13)A, b=10.748(2)A, c=17.778(4)A, beta=94.266(5) degrees , and V=1078.5(4)A(3) with Z=4 for d(calc)=1.495 g/cm(3). Calculations of the vibrational frequencies have been carried out on the basis of normal coordinate analysis using simple general valence force field in Wilson's GF matrix method with the SPSIM computer program. With the help of this modern technique we were able to complete the assignment of the vibrational spectrum of the title compound.