Similar reactions of 2,6-dipicolinoylbis(N,N-diethylthiourea) (H2L(a)) with: (i) Ni(NO3)2·6H2O, (ii) a mixture of Ni(NO3)2·6H2O and AgNO3, (iii) a mixture of Ni(OAc)2·4H2O and PrCl3·7H2O and (iv) a mixture of Ni(OAc)2·4H2O and BaCl2·2H2O give the binuclear complex [Ni2(L(a))2(MeOH)(H2O)], the polymeric compound [NiAg2(L(a))2]∞, and the heterobimetallic complexes [Ni2Pr(L(a))2(OAc)3] and [Ni2Ba(L(a))3], respectively. The obtained assemblies can be used for the build up of supramolecular polymers by means of weak and medium intermolecular interactions. Two prototype examples of such compounds, which are derived from the trinuclear complexes of the types [MLn(III)(L)2(OAc)3] and [MBa(L)3], are described with the compounds {[CuDy(III)(L(a))2(p-O2C-C6H4-CO2)(MeOH)4]Cl}∞ and [MnBa(MeOH)(L(b))3]∞, H2L(b) = 2,6-dipicolinoylbis(N,N-morpholinoylthiourea).

Reactions of (NBu4)[ReOCl4] and 3,3,3',3'-tetraalkyl-1,1'-isophthaloylbis(thioureas), H2phth(R2tu)2 where R = Et, i-Bu, in hot MeOH with the addition of Et3N give red products of the composition [ReO(OMe){phth(R2tu)2}]2 (8a, R = Et; 8b, R = i-Bu). X-ray structures of 8 reveal symmetric binuclear complexes containing two almost coplanar organic ligands, each of which coordinates to two rhenium centers via the two bidentate-O,S moieties. The octahedral coordination spheres of the rhenium atoms are completed by each one oxo and one methoxido ligand which are directed perpendicular to the plane defined by the {phth(R2tu)2}(2-) ligands. While in 8a, both methoxido ligands point to the same side of the described plane and form a syn isomer, the MeO(-) ligands in 8b are located at opposite sides and form an anti isomer. Studies in solution show that there exists a reversible equilibrium between the anti and syn isomers. Dimerization/condensation of complexes 8 with the formation of tetranuclear complexes of the composition [{ReO{phth(R2tu)2}}2O]2 (9) and/or polynuclear species is observed in solutions, which do not contain MeOH.

Thiocarbamoylbenzimidoyl chlorides, PhC(Cl)═N-(C═S)-NR(1)R(2), react with 2-(iminodiacetic acid)benzylamine under formation of the potentially pentadentate ligands H3L (R(1), R(2) = Et) and H3L-COOEt (R(1) = Me, R(2) = C6H4-4-COOEt) in high yields. Hydrolysis of H3L-COOEt in NaOH/MeOH gives quantitatively another benzamidine ligand H3L-COOH. The novel ligands readily react with (NBu4)[MOCl4] (M = Re, Tc) under formation of stable complexes with the general composition [MO(L)], in which they are triply deprotonated and fully occupy the remaining five coordination positions of the {MO}(3+) cores. In a "proof-of-principle" reaction for possible bioconjugations, the complex [ReO(L-COOH)] has been labeled with triglycine ethyl ester in high yields.

The reaction of isophthaloylbis(N,N-diethylthiourea), HL, with FeCl·6HO gives the dinuclear tris-complex [Fe(L)] (5), possessing a cryptand-like structure. A similar reaction with the ligand 2,6-dipicolinoylbis(N,N-diethylthiourea), HL, however, results in the formation of the anionic, mononuclear Fe(III) complex [Fe(L)] (6), which could be isolated as its "Tl salt" by the subsequent addition of Tl(NO). A tighter view to the solid state structure of the obtained product, however, characterizes compound 6 as a one-dimensional coordination polymer, in which four-coordinate Tl ions connect the {[Fe(L)]} units to infinite chains. When Fe ions and Tl ions are added to HL simultaneously in a one-pot reaction, a different product is obtained: a cationic trinuclear complex of the composition {M⊂[Fe(L)]}. It has been isolated as a PF salt and represents a {2}-metallacryptate with a nine-coordinate Tl ion in the central void. Structurally related products of the compositions {M⊂[Fe(L)]}(PF) (M = Na, K, Rb) (8(PF)) could be isolated from analogous reactions with alkaline salts instead of Tl(NO). {2}-Metallacryptates with larger central voids were synthesized with the ether-spaced aroylbis(N,N-diethylthiourea) HL. The compounds {M⊂[Fe(L)]}(PF) (M = K, Rb, Tl or Cs) (9(PF)) were prepared by a similar protocol like those with HL with the simultaneous addition of the metal ions to a solution of HL. Due to the larger spacer between the aroylthiourea units, the coordination number of the central M ions is 12 by six carbonyl and six ether oxygen atoms. All products were characterized by elemental analysis, IR spectroscopy, and X-ray structure analysis. Cyclic voltammetric studies were carried out with the three representative complexes [Fe(L)], {K⊂[Fe(L)]}(PF), and {K⊂[Fe(L)]}(PF). The obtained voltammograms indicate the dependence of the redox properties of the oligonuclear systems on the conjugation in the organic backbones of the ligands.

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The reaction of isophthaloylbis( N, N-diethylthiourea), HL, with UO(CHCOO)·2HO and NEt as a supporting base gives a tetranuclear, anionic complex of the composition [{UO(L)}(OAc)], in which the uranyl ions are S, O-chelate bonded. Each two of them are additionally linked by an acetato ligand. Similar reactions of various uranyl starting materials (uranyl acetate, uranyl nitrate, (NBu)[UOCl]) with corresponding pyridine-centered ligands (pyridine-2,6-dicarbonylbis( N, N-dialkylthioureas), HL) yield mononuclear, neutral compounds, in which the thiourea derivatives are coordinated as S, N, N, N, S-five-dentate chelators. The equatorial coordination spheres of the formed hexagonal bipyramidal complexes [UO(L)(solv)] are completed by solvent ligands (HO, MeOH, or DMF). Attempted reactions without a supporting base result in decomposition of the organic ligands and the formation of hexanuclear uranyl complexes with pyridine-2,6-dicarboxylato ligands, while the use of an excess of base results in condensation and the formation of dinuclear [{UO(L)(μ-OMe)}] complexes. A stable complex of the composition [UO(L)] results from reactions of common uranyl starting materials with 2,2'-bipyridine-6,6'-dicarbonylbis( N, N-diethylthiourea) (HL). The equatorial coordination sphere of the neutral, hexagonal bipyramidal complex is occupied by an SNS donor atom set, which is provided by the hexadentate organic ligand. While the uranium complexes with {L} and {L} are labile and rapidly decompose in acidic solutions, [UO(L)] is stable over a wide pH range, and the ligand readily extracts uranyl ions from aqueous solutions into organic solvents.

The A 2[ReF6] (A = K, Rb, Cs) salts are isotypic and crystallize in the K2[GeF6] structure type.

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