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Apoyo científico y técnico del CACTI Nine potentially S,N,Npy-tridentate thiosemicarbazones (HL) derived from pyridine-2-carbaldehyde or 1-(2-pyridyl)ethanone have been prepared and fully characterized. The X-ray crystal structures of six of them and two hydrochlorides were determined and analyzed. The reaction of the [ReX(CH3CN)2(CO)3]/[ReX(CO)5] (X = Cl and Br) precursors with these ligands yielded different kinds of compounds: the adducts [ReX(HL)(CO)3], in which the ligands were S,N-bidentate; the trinuclear species [Re3Cl2(L23)(HL23)(CO)9]; and the thiosemicarbazonate compounds [Re(L)(CO)3], where the ligand is S,N,Npy-tridentate. Besides, the reaction in methanol or ethanol of the thiosemicarbazones derived from aldehydes yielded S,N,Npy-tridentate hemiaminal cationic [Re(HLOR)(CO)3]X and neutral [Re(LOMe)(CO)3] complexes after the coordinated ligand underwent addition of the alcohol group to the imine bond. The reactivity of the complex [ReX(HL)(CO)3] in MeOH and NEt3 led to the formation of dinuclear [Re2(L)2(CO)6], where the thiosemicarbazonate is again S,N-bidentate. The influence that the substituents on the thiosemicarbazone ligands have on the stability of the complexes and the effect of the reaction medium on the resulting compounds have been analyzed. Agencia Estatal de Investigación | Ref. PID2019-110218RB-I00 Universidade de Vigo/CISUG

Nine potentially S,N,N

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG Apoyo científico y técnico del CACTI Four acyl-hydrazones derived from 5-hydroxypicolinohydrazide and 4-hydroxybenzaldehyde (HL11), 2-fluoro-4-hydroxybenzaldehyde (HL12), 2,4-dihydroxybenzaldehyde (HL13) or 2-pyridinecarboxaldehyde (HL14) and two hydrazones derived from 2-hydrazino pyridine and 4-dimethylaminobenzaldehyde (HL21) or 4-diethylamino-2-hydroxybenzaldehyde (HL22) were synthesized and their X-ray structures determined. Twelve rhenium(I) complexes of formula [ReX(HLn)(CO)3] (X = Cl, Br) were obtained by treating these ligands with [ReX(CH3CN)2(CO)3], and the structures of some representative compounds were determined by X-ray diffraction. The coordination geometry around rhenium(I) can be described as octahedral, with three carbon atoms in a fac configuration, the halogen atom and two nitrogen atoms from the hydrazone chain and the pyridine group, respectively. The carbonyl group of the acyl-hydrazone ligands does not participate in coordination in any of complexes HL11–HL14. The coordination mode of the ligands in all complexes could be established by comparing the IR and 1H NMR spectra. Formation of the hydrazonate complexes only proved possible with the derivatives of HL22. A study of the corresponding single crystal showed the presence of the dimer [Re2(L22)2(CO)6], in which the phenolate group of the ligand of the dimer partner coordinates to rhenium after deprotonation. This same group is used to bind to the rhenium atom of the dimer partner at the position released by the halide. Agencia Estatal de Investigación | Ref. PID2019-110218RB-I00 Universidade de Vigo/CISUG

The reaction of fac-[ReX(CH3CN)2(CO)3] (X = Cl, Br) with N-phenyl-[4-(dimethylamino)benzaldehyde] thiosemicarbazone (HLA) or N-4-methoxybenzyl-[4-(dimethylamino)benzaldehyde] thiosemicarbazone (HLB...

Mol­ecules of the complex fac-[ReCl(4-pyOH)2(CO)3] (4-pyOH is 4-hy­droxy­pyridine) and 4-pyridone are associated in ladder chains by hydrogen and coordination bonds., The asymmetric unit of the title compound, [ReCl(C5H5NO)2(CO)3]·C5H5NO, contains one mol­ecule of the complex fac-[ReCl(4-pyOH)2(CO)3] (where 4-pyOH represents 4-hy­droxy­pyridine) and one mol­ecule of pyridin-4(1H)-one (4-HpyO). In the mol­ecule of the complex, the Re atom is coordinated to two N atoms of the two 4-pyOH ligands, three carbonyl C atoms, in a facial configuration, and the Cl atom. The resulting geometry is slightly distorted octa­hedral. In the crystal structure, both fragments are associated by hydrogen bonds; two 4-HpyO mol­ecules bridge between two mol­ecules of the complex using the O=C group as acceptor for two different HO– groups of coordinated 4-pyOH from two neighbouring metal complexes. The resulting square arrangements are extented into infinite chains by hydrogen bonds involving the N—H groups of the 4-HpyO mol­ecule and the chloride ligands. The chains are further stabilized by π-stacking inter­actions.

A supramolecular synthesis process in methanol of a combination of several resorcinol-thiosemicarbazones (TSC) and two N,N′-divergent bipyridines (BP) led to the isolation of 14 cocrystals, some of which contained solvent in the crystal lattice. The main hydrogen bonded motifs have been identified, and some key structural factors have been analyzed by theoretical calculations. Structurally, the 14 cocrystals can be grouped into two main types. The first type is characterized by the formation of TSC/BP cyclic arrangements involving a solvent and also by the absence of the intramolecular O–H···N, S(6), interaction in the TSC component. The second type is characterized by TSC/BP acyclic associations, in most cases without the inclusion of solvent, and the usual intramolecular O–H···N, S(6), interaction is maintained in the TSC component.

Five thiosemicarbazones (H2Ln) derived from 4,6-diacetylresorcinol (n = 1–4) and salicylaldehyde (n = 5) have been synthesized and spectroscopically characterized. Single crystal X-ray diffraction studies on some of the complexes show that the molecular structure is dominated by intramolecular hydrogen bonds involving the O(1)–H group of the resorcinol/salicylaldehyde group and the azomethinic nitrogen atom and sulfur atom of the thiosemicarbazone arm. All of the ligands react with fac-[ReCl(CO)3(CH3CN)2] in the presence of NEt3 to form the stable anionic complexes [NHEt3][fac-[Re(Ln)(CO)3] (1–5). The thiosemicarbazonate ligand, as suggested by spectroscopic data and confirmed by X-ray diffraction, acts as a tridentate S,N,O system. The complexes are stable in solution for weeks, although other dimeric species were also detected by X-ray diffraction analysis. The reaction of fac-[99mTc(CO)3(H2O)3]+ with the appropriate ligand at 100 °C for 30 min yielded the complexes [fac-[99mTc(Ln)(CO)3]− (Tc1–Tc5). The radiochemical yield and purity were determined by HPLC and their chemical identity was ascertained by comparing their radiochromatogram with the chromatogram of the rhenium congeners (1–5). The results of biodistribution studies in mice on the five technetium compounds showed rapid blood clearance and fast liver uptake that slowly cleared into the intestines, a finding that indicates the hepatobiliary tract as the major excretory pathway. HPLC analysis of urine and blood serum samples from mice injected with the 99mTc complexes confirmed their in vivo stability since the predominant radiochemical species had the same retention time as the corresponding injected compound.

The inclusion of a methyl­ene group at the thio­amidic N atom of the acetone thio­semicarbazone derivative endows the mol­ecule with greater flexibility and different pathways of association compared to those usually observed in the crystalline structures of these compounds., The structure of the title compound, C11H15N3OS, shows the flexibility due to the methyl­ene group at the thio­amide N atom in the side chain, resulting in the mol­ecule being non-planar. The dihedral angle between the plane of the benzene ring and that defined by the atoms of the thio­semicarbazide arm is 79.847 (4)°. In the crystal, the donor–acceptor hydrogen-bond character of the –OH group dominates the inter­molecular associations, acting as a donor in an O—H⋯S hydrogen bond, as well as being a double acceptor in a centrosymmetric cyclic bridging N—H⋯O,O′ inter­action [graph set R 2 2(4)]. The result is a one-dimensional duplex chain structure, extending along [111]. The usual N—H⋯S hydrogen-bonding association common in thio­semicarbazone crystal structures is not observed.

The mol­ecular and crystal structures of a monoclinic polymorph of 1,2-bis­[(1-methyl-1H-tetra­zol-5-yl)sulfan­yl]ethane (BMTTE) are described., The synthesis and crystal structure of a monoclinic (P21/c) polymorph of the title compound, C6H10S2N8, are reported. The mol­ecule has pseudo-twofold rotational symmetry, with the tetra­zole rings being inclined to one another by 5.50 (6)°. In the crystal, mol­ecules are linked by C—H⋯N hydrogen bonds, forming chains propagating along [101] and enclosing R 2 2(20) ring motifs. The chains are linked by offset π–π inter­actions involving the tetra­zole rings [inter­centroid distances vary from 3.3567 (7) to 3.4227 (7) Å], forming layers parallel to the ac plane. The crystal structure of the triclinic polymorph (P ) has been described previously [Li et al. (2011 ▸). Acta Cryst. E67, o1669].