Yang Farina

Diorganotin(IV) Derivatives of N-Methyl p-Fluorobenzo-Hydroxamic Acid: Preparation, Spectral Characterization, X-ray Diffraction Studies and Antitumor Activity

Three diorganotin(IV) complexes of the general formula R2Sn[RcC(O)N(RN)O] (Rc = aryl, RN = Alkyl) have been synthesized by refluxing in toluene the corresponding diorganotin(IV) oxides with the free ligand N-methyl p-fluorobenzohydroxamic acid, using a Dean and Stark water separator. The ligand was derived from the reaction of the corresponding p-fluorobenzoyl chloride and N-methylhydroxylamine hydrochloride in the presence of sodium hydrogen carbonate. The isolated free ligand and its respective diorganotin compounds have been characterized by elemental analysis, IR and 1H-, 13C-, 119Sn-NMR spectroscopies. The crystal structures of the diorganotin complexes have been confirmed by single crystal X-ray diffraction methods. The investigations carried out on the diorganotin(IV) complexes of N-methyl p-fluorobenzohydroxamic acid confirmed a 1:2 stoichiometry. The complex formation took place through the O,O-coordination via the carbonyl oxygen and subsequent deprotonated hydroxyl group to the tin atom. The crystal structures of three diorganotin complexes were determined and were found to adopt six coordination geometries at the tin centre with coordination to two ligand moieties.

(E)-3,4-Dihydroxy-benzaldehyde 4-ethyl-thio-semicarbazone.

The title compound, C10H13N3O2S, was prepared by condensation of 3,4-dihydroxybenzaldehyde with 4-ethyl-3-thiosemicarbazide. The molecule adopts an E configuration with respect to the C=N bond. One of the OH substituents on the dihydroxybenzene ring is disordered over the two possible 3-positions on either side of the ordered 4-hydroxy group. The occupancy of the major disorder component refined to 0.633 (7). The molecule is essentially planar, with an r.m.s. deviation through all non-H atoms of 0.0862 Å. An intramolecular N—H⋯N hydrogen bond forms between the outer amine residue and the imine N atom, generating an S(5) ring motif and contributing to the planarity of the molecule. In the crystal structure, an extensive network of classical O—H⋯O, O—H⋯S and N—H⋯S hydrogen bonds and weak C—H⋯O and S⋯O [3.301 (3) Å] interactions link molecules into sheets running approximately parallel to the ab plane.

CRYSTAL STRUCTURE OF DIBUTYLTIN BIS(N,N-DIISOPROPYL)DITHOCARBAMATE

hydrogen a toms are shown as spheres of arbitrary radii. Selected bond dis tances and angles : S n l — C I = 2.13(1), S n l — C I / = 2.13(1), S n l — S I = 2.530(2), S n l — S I ; = 2.530(2), S n l — S 2 = 2 .944(2) , S n l — S 2 ; = 2.944(2) Ä; C I — S n l — C I ; = 131.5(6), C I — S n l — S I = 108.1(2), C I — S n l — S I ; = 108.1(2), C I — S n l — S 2 = 83.8(1), C I — S n l — S2; = 83.8(1), C I ; — S n l — SI = 108.1(2), C I / — S n l — S I ; = 108.1(2), C I / — S n l — S 2 = 83.8(1), C I / — S n l — S 2 ; = 83.8(1), S I — S n l — S l ; = 81.7(1), S I — S n l — S 2 = 64.5(1) , S I — S n l — S2; = 146.2(1), S I / — S n l — S 2 = 146.2(1), S I / — S n l — S 2 / = 64.5(1), S 2 — S n l — S 2 ; = 149.3(1)°. S y m m e t r y t ransformation: / = 0.5 — χ , 1.5 — y , z.

trans-Bis(3-hydroxy-2-phenyl-4H-1-benzopyran-4-onato)bis(pyridine)nickel(II)

3-Hydroxyflavone and bipyridyl ligands coordinate to the Ni II centre in an octahedral arrangement, giving the title complex, [Ni(C 15 H 9 S 3 ) 2 (C 5 H 5 N) 2 ]. Since the Ni atom lies on a centre of symmetry, all the trans O-Ni-O and N-Ni-N bond angles are 180° ; those of O-Ni-N are close to 90°. The Ni-O(carbonyl), Ni-O(hydroxy) and Ni-N distances are 2.067(2), 2.023(2) and 2.180(2) A, respectively. All the C-C bond distances are normal with values between 1.366 (3) and 1.406(4) A, except those which are close to the coordinated C-O bonds : C(1)-C(2), C(2)-C(3) and C(9)-C(10) are 1.457 (4), 1.445 (3) and 1.462 (4) A, respectively. All rings are almost planar, except those involving coordinated O atoms. The dihedral angles between the flavonato planes and the pyridyl ligands are quite large with values of ca 84°. The angles between the planes in the hydroxyflavone ligand are less than 10°.

3-[(E)-(4-Chloro-benzyl-idene)amino]-1-phenyl-thio-urea.

In the title compound, C14H12ClN3S, the dihedral angle between the terminal benzene rings is 56.6 (2)°; the benzene rings lie to the same side of the molecule. The major twist in the molecule occurs around the Car—N bond (ar is aromatic) [C—N—C—C = 49.9 (5)°]. The configuration about the N=C bond [1.271 (4) Å] is E. The amine H atoms lie on opposite sides of the molecule with one forming an intramolecular N—H⋯N(imine) hydrogen bond and an S(5) ring. In the crystal, centrosymmetric dimers are formed via {⋯HNC=S}2 synthons.

(Thiocyanato-N)tris(triphenylphosphine)-silver(I) chloroform solvate

Crystals of [Ag(NCS)(C18H15P)3].CHCl3 consist of discrete [Ag(PPh3)3(NCS)] molecules, in which the Ag atom is tetrahedrally surrounded by three P atoms of the PPh3 groups and the N atom of the isothiocyanate ligand, and chloroform molecules. The coordination polyhedron around the Ag atom is distorted with angles at Ag ranging from 102.58 (10) to 114.73 (3)°. The Ag—N—C angle is 159.6 (3)°.

3-(2-Hy-droxy-phen-yl)-1-{(E)-[1-(pyrazin-2-yl)ethyl-idene]amino}-thio-urea monohydrate.

In the title compound, C13H13N5OS·H2O, the thiourea molecules closely resemble each other and are approximately planar; the dihedral angles formed between the terminal benzene rings are 7.88 (8) and 7.20 (8)°, respectively. The observed planarity correlates with the presence of bifurcated N—H⋯(O,N) hydrogen bonds. In the crystal, the molecules are connected into supramolecular double chains via a combination of N—H⋯S (linking the two independent molecules), O—H⋯O and O—H⋯N (linking dimeric aggregates into a supramolecular chain via hydroxy–water, water–water and water–pyrazine interactions) and O—H⋯S hydrogen bonds (connecting two chains). The chains are further connected by C—H⋯N and C—H⋯S interactions.

3,4-Dihydroxy­benzaldehyde thio­semi­carbazone

The asymmetric unit of the title compound, C8H9N3O2S, contains three independent molecules which are stacked approximately over each other. In the crystal structure, centrosymmetric pairs of molecules are formed through intermolecular hydroxy–hydroxy O—H⋯O and hydroxy–sulfur O—H⋯S hydrogen bonds which are, in turn, linked into a two-dimensional network by N—H⋯O(hydroxy) hydrogen bonds.

Bis­[N-(2-hydroxy­ethyl)-N-methyl­di­thiocarbamato-S,S′]­di­phenyl­tin

The Sn atom in the title compound, [Sn(C6H5)2(C4H8NOS2)2], is six-coordinate in a cis–C2SnS4 octahedral environment.

Bis­[N,N‐bis(2‐hydroxy­ethyl)­di­thio­carbamato‐S,S′]di­phenyl­tin(IV)

The Sn atom in the title compound, [Sn(C6H5)2(C5H10NO2S2)2], is six-coordinate in a cis-C2SnS4 octahedral environment.