Terminal Thio-cyanate Anions Research Articles

Combined experimental and computational approach to the structure of a new nickel(II) complex with tridentate Schiff base ligand

A combined experimental and theoretical study on a new complex [NiL(NCS)], derived from the Schiff base ligand HL, (E)-2-methoxy-6-(((pyridin-2-ylmethyl)imino)methyl)phenol is described herein. X-ray structure reveals that metal center of the complex has a square planar environment with a N3O donor set from the ligand and terminal thiocyanate anion. In the solid state, π—π stacking interactions lead to a one-dimensional arrangement with alternating short and long Ni…Ni distances. The different isomeric forms of the ligand can provide alternative molecular structures for the nickel(II) complex. Density functional theory calculations at B3LYP/6-311+G(d,p) level were performed to elucidate the structure and stability of the possible isomeric forms of the complex.

Crystal structure of bis-(aceto-nitrile-κN)bis-(4-benzoyl-pyridine-κN)bis-(thio-cyanato-κN)cobalt(II).

The crystal structure of the title compound, [Co(NCS)2(C2H3N)2(C12H9NO)2], consists of cobalt(II) cations that are octa-hedrally coordinated by the N atoms of two terminal thio-cyanate anions, two aceto-nitrile mol-ecules and two 4-benzoyl-pyridine ligands. The discrete complexes are located on centres of inversion. They are connected by weak inter-molecular C-H⋯O and C-H⋯S hydrogen-bonding inter-actions between one of the pyridine H atoms and the carbonyl O atom, and between one of the methyl H atoms of the aceto-nitrile mol-ecule and the thio-cyanate S atoms into layers parallel to (101). No pronounced inter-molecular inter-actions are observed between these layers.

Crystal structure of di-aqua-bis-(2,6-di-methyl-pyrazine-κN (4))bis-(thio-cyanato-κN)cobalt(II) 2,5-di-methyl-pyrazine monosolvate.

In the crystal structure of the title compound, [Co(NCS)2(C6H8N2)2(H2O)2]·C6H8N2, the CoII cation is coordinated by the N atoms of two terminal thio­cyanate anions, the O atoms of two water mol­ecules and two N atoms of two 2,6-di­methyl­pyrazine ligands. The coordination sphere of the resulting discrete complex is that of a slightly distorted octa­hedron. The asymmetric unit comprises a CoII cation and half of a 2,5-di­methyl­pyrazine ligand, both of which are located on centres of inversion, and a water ligand, a 2,6-di­­methyl­pyrazine ligand and one thio­cyanate anion in general positions. In the crystal, the discrete complexes are arranged in such a way that cavities are formed in which the 2,5-di­methyl­pyrazine solvent mol­ecules are located. The coordination of the 2,5-di­methyl­pyrazine mol­ecules to the metal is apparently hindered due to the bulky methyl groups in vicinal positions to the N atoms, leading to a preferential coordination of the 2,6-di­methyl­pyrazine ligands. The discrete complexes are linked by O—H⋯N hydrogen bonds between one water H atom and the non-coordinating N atom of the 2,6-di­methyl­pyrazine ligands. The remaining water H atom is hydrogen bonded to one N atom of the 2,5-di­methyl­pyrazine solvent mol­ecule. This arrangement leads to the formation of a two-dimensional network extending parallel to (010).

Bis(acetylacetonato-κ2O,O′)(pyridine-κN)(thiocyanato-κN)manganese(III): a redetermination using data from a single crystal

In the crystal structure of the title compound, [Mn(C5H7O2)2(NCS)(C5H5N)], the Mn3+ cation is coordin­ated by two acetyl­acetonate anions, one terminal thio­cyanate anion and one pyridine ligand within a slightly distorted octa­hedron. The asymmetric unit consists of half a complex mol­ecule with the Mn3+ cation, the thio­cyanate anion and the pyridine ligand located on a mirror plane. The acetyl­acetonate anion is in a general position. The title compound was previously described [Stults et al. (1975 ▶). Inorg. Chem. 14, 722–730] but could only be obtained as a powder. Suitable crystals have now been obtained for a high-precision single-crystal structure determination.

Poly[μ4-sulfido-tris(thiocyanato-κN)tris(μ3-1,2,4-triazolato-κ3N1:N2:N4)tetrazinc(II)]: a three-dimensional zinc sulfide coordination polymer

The title compound, [Zn(4)(C(2)H(2)N(3))(3)(NCS)(3)S](n), is a three-dimensional coordination polymer consisting of tetrahedral SZn(4) clusters bridged by triazole ligands. In the tetrahedral unit, three Zn atoms are connected to six bridging triazolate ligands, whereas the fourth Zn atom (site symmetry 3m) is bonded to three terminal thiocyanate anions that protrude into the void space created by the Zn-triazolate network. The network prototype is simple cubic, but a strong distortion along a body diagonal and the imposition of a polar direction by the arrangement of the molecular constituents lead to the trigonal space group R3m. This study demonstrates the use of the 3-mercapto-1,2,4-triazole ligand as an effective source for sulfide ions in the synthesis of sulfide-based coordination polymers.

Synthesis, Crystal Structures and Antibacterial Activities of Two Schiff Base Copper(II) Complexes

Two new mononuclear Schiff base copper(II) complexes, [CuBr2L] (1) and [CuBr(NCS)L] (2), where L=N,N‐dimethyl‐N′‐(1‐pyridinylmethylidene)propane‐1,3‐diamine, have been obtained from a similar synthetic procedure. The complexes were characterized by elemental analyses and single crystal X‐ray diffraction. In 1, the copper(II) ion is five‐coordinated in a distorted square‐pyramidal configuration, with three N atoms of L and one terminal Br atom defining the basal plane and with the other terminal Br atom occupying the apical position. The coordination of the copper(II) ion in 2 is similar to that of 1, but the basal terminal Br atom is replaced by the N atom of a terminal thiocyanate anion. The Schiff base ligand L and the two copper(II) complexes show potent antibacterial activities.

Synthesis, Crystal Structure and Fluorescence of A 1-D Polymeric Zinc(Ii) Complex with Pyrazine-2-Carboxylate as a Bridging Ligand

A one-dimensional chain complex {[Zn(pyz)(SCN)(H2O)2]·H2O}∞ (pyz = pyrazine-2-carboxylic anion) has been synthesized and its crystal structure determined by X-ray crystallography. The complex crystallizes in an orthorhombic system and the space group is P2 12121 with a = 6.873(3), b = 9.847(4), c = 16.466(7) Å. The Zn(II) ion is located in a distorted octahedral environment with two oxygen atoms O(3) and O(4) from terminal ligands of two water molecules, another oxygen atom O(1) from the carboxylate group of pyz, and three nitrogen atoms, N(1), and N(2A) from two different pyz and N(3) from a terminal thiocyanate anion, in which a chelated five-membered ring is formed by coordination of O(1) and N(1) to the Zn(1) atom. Therefore, an infinite zigzag chain consisting of Zn(II) ions and pyz anions is constructed and the chains are linked together with hydrogen bonding from coordinated and uncoordinated water molecules. The fluorescence spectra for the bridging ligand Na(pyz) and the complex were measured at room temperature in aqueous solution and in the solid state.