Georgina Espinosa-Pérez

Tetrahedral versus square-planar NiS4 core in solid-state bis(dithioimidodiphosphinato)nickel(II) chelates. Crystal and molecular structures of Ni[(SPR2) (SPPh2) N]2 (R = Ph, Me)

Abstract Bis(dithioimidodiphosphinato)nickel(II) chelates, Ni[(SPR2) (SPPh2)N]2 (R = Ph (1), Me (2)) were prepared by methathesis reactions between NiCl2·6H2O and the corresponding potassium dithioimidodiphosphinate, in methanol. Compound 1 crystallizes in the triclinic space group P-1, a = 13.336(2), b = 18.580(2), c = 18.670(2) A , α = 90.10(2), β = 93.00(2), γ = 98.21(2)°, Z = 4 , and contains two independent molecules in the unit cell. Compound 2 crystallizes in the monoclinic space group P2 1 /c, a = 13.161(2), b = 10.737(5), c = 12.101(4) A , β = 108.38(2)°, Z = 2 . In both compounds the 1,3-dithiophosphorus ligands act as symmetrical monometallic biconnective (isobidentate chelating) units and the resulting NiS2P2N rings are non-planar. Compound 1 contains a tetrahedral NiS4 core (mean NiS 2.239 A, SNiS 111.9° (endocyclic), 108.2° (exocyclic)), while compound 2 exhibits a square-planar NiS4 core (mean NiS 2.239 A, SNiS 98.3° (endocyclic), 81.1° (exocyclic)). The structures are discussed in relation to previously reported Ni(II) derivatives of 1,1-dithiophosphorus ligands.

Crystal and molecular structure of 1-phenyl-1H-tetrazole-5-thiolato-trimethyltin(IV), Me3SnSCN4Ph, exhibiting unusual trimeric associations through intermolecular N → Sn bonds.

Abstract The title compound is rhombohedral, space group R3, with a = 18.097(4), c = 10.832(5) A, Z = 9, Dc = 1.658 g cm−3. The crystal contains trimeric [Me3SnSCN4Ph]3 units in which the heterocyclic ligand is bridging two metal atoms (Sn(1)-S(1) 2.565(4) A, N(3) → Sn(1a) 2.747(14) A). Additionally, weak intramolecular Sn(1) ⋯ N(4) secondary bonds of 3.285(12) A are also present, thus leading to a bimetallic triconnective coordination pattern of the ligand.

A true square-planar tin(II) spiro complex: molecular structure of bis(imidotetraphenyldiselenodiphosphino-Se,Se′)tin(II) and its distorted tetragonal-pyramidal isomer

The yellow complex [Sn{N(SePPh2)2-Se,Se′}2] is the first example of a true square-planar spiro tin(II) compound; the structure of the distorted tetragonal-pyramidal isomer is also described.

New organotin(IV) derivatives of 1-phenyl-1H-tetrazole-5-thiol. Crystal and molecular structure of 1∞[Bz3SnSCN4Ph], a polymer built through secondary intermolecular Sn⋯N bonds

Abstract Di- and triorganotin(IV) derivatives of 1-phenyl-1H-tetrazole-5-thiol, RnSn(SCN4Ph)4−n (R = Me, Bz; n = 2, 3), were prepared by reacting the corresponding organotin chlorides with the ammonium salt of the thiotetrazolato anion. The title compounds were characterized by means of IR and 1H, 13C and 119Sn NMR spectroscopy. The molecular structure of Bz3SnSCN4Ph was investigated using X-ray diffractometry. Data on a redetermination of the crystal and molecular structures of n-Bu2Sn(SCN4Ph)2 are also included, and a comparative discussion of the two structures is presented.

Bis(tetraphenylimidothioxodiphosphinate-S,O)lead(II) · benzene, [Pb{SO(PPh2)2N}2] · C6H6: A new asymmetric chelate compound exhibiting dimeric association through intermolecular Pb…S interactions

Abstract The tetraphenylimidodithioxodiphosphinate (SO(PPh 2 ) 2 N) ion forms a stable bis-chelate with Pb II . The crystal and molecular structure of [Pb{SO(PPh 2 ) 2 N} 2 ] · C 6 H 6 was determined by X-ray diffractometry. Units of [Pb{SO(PPh 2 ) 2 N} 2 ] are associated through intermolecular Pb…S interactions, forming a dimer. This complex displays a very distorted ϕ-trigonal bipyramidal structure at the lead atom with a vacant equatorial position, which may be accounted for by the presence of intermolecular lead-sulphur interactions.

Palladium(II) and platinum(II) complexes of 6-methyl-2-acetylpyridine 3-hexamethyleneiminylthiosemicarbazones: A structural and spectral study

Abstract The reaction of 6-methyl-2-acetylpyridine 3-hexamethyleneiminyl-thiosemicarbazone, H6MAchexim, with potassium tetrachloropalladate(II) and tetrachloroplantinate(II) in methanol afforded the complexes [Pd(6MAchexim)Cl] and [Pt(6MAchexim)Cl], respectively. The X-ray crystal structure determination of both shows that anions of H6MAchexim coordinate in a planar conformation to the central palladium(II) or platinum(II) via the pyridyl nitrogen, azomethine nitrogen and thiolato sulfur atoms. The complexes have also been characterized by spectroscopic techniques (IR, UV–VIS and 1H NMR).

Tetrachlorocuprate(II) salts of heterocyclic aminoguanidonium (guanylhydrazonium) ions

Abstract Condensation of aminoguanidine with 2-formylpyridine, 2-benzoylpyridine and 2,6-diacetylpyridine results in the aminoguanidones, HFogu, HBzgu and H22,6Acgu2, respectively. Reaction of the heterocyclic aminoguanidone in a mixture of hydrochloric acid–ethanol with copper(II) chloride produces the following mixed salts: [H3Fogu][CuCl4], (1), [H3Bzgu]2 [CuCl4]Cl2·H2O, (2), and [H52,6Acgu2][CuCl4]Cl·H2O, (3). Their crystal structures, as well as their ESR and UV spectra, have been obtained. The influence on the geometry of the [CuCl4]2− of the NH⋯ClCu hydrogen bonds, in the context of charged compensation hypothesis, has been evaluated.

1-Oxa-4,6-Dithia-5-Arsocane and 1,3,6-Trithia-2-Arsocane Dithiocarbamates Competition Between Transannular and Exocyclic Secondary Bonding to Arsenic

1-oxa-4,6-dithia-5-arsocane morpholinyldithiocarbamate (1) and 1,3,6-trithia-2-arsocane 2-diethyldithiocarbamate (2) have been prepared by reacting the corresponding sodium dithiocarbamates with 1-oxa-4,6-dithia-5-arsocane or 1,3,6-trithia-2-arsocane. (1) and (2) were characterized by elemental analyses, IR, MS, 1H and 13CNMR. The X-ray single-crystal molecular structures of (1) [monoclinic, a = 9.931(5), b = 18.253(5), c = 8.076(3) A; β = 92.56(2)°; V = 1462.5(7) A3; space group P21/c; Z = 4; R = 4.33%] and (2) [monoclinic, a = 7.830(2), b = 10.465(2), c = 19.025(6) A; β = 95.82(2)°; V = 1550.8(10) A3; space group P21/c; Z = 4; R = 3.41%], show that the compounds are monomeric and contain an asymetric monometallic biconnective dithiocarbamate ligand with a large distortion in the geometry around the As and a weak heterocyclic arsocane transannular secondary interaction.

Synthesis and characterization of phenoxarsin-10-yl diorganodithiophosphinates. A folded phenoxarsine system in the first dimeric organoarsenic(III) 1,1-dithiolate associated through As ⋯ S secondary bonding

Some phenoxarsin-10-yl diorganodithiophosphinates, O(C6H4)2AsS2PR2(R = Me, Et or Ph), have been prepared by treating 10-chlorophenoxarsine with salts of the corresponding dithio compounds in CH2Cl2. The compounds were characterized by IR, mass spectrometry and 1H, 13C and 31P NMR spectroscopy and the crystal structure of O(C6H4)2AsS2PPh2 has been determined. The compound is monoclinic, space group P2/n, a= 8.925(6), b= 22.028(8), c= 11.341(5)A, β= 100.70(2)° and Z= 4. It exhibits a dimeric, quasi-tricyclic structure based upon intra- and inter-molecular As ⋯ S secondary bonds (3.402 and 3.381 A, respectively), which is unique in arsenic–sulfur chemistry. The phenoxarsine unit is non-planar with a dihedral angle of 154.4° between the planes of the two aromatic rings.

A mixed-valence dimanganese complex synthesized from the [Ph2P(O)NP(O)Ph2]− anion with [BrMn(CO)5]

Abstract The reaction of the [Ph2P(O)NP(O)Ph2]− anion with [BrMn(CO)5] in refluxed dichloromethane afforded the mixed-valence complex [Mn2(CO)3{Ph2P(O)NP(O)Ph2-μ-O,O′}3] (1). The single-crystal X-ray analysis of 1 shows that its overall geometry can be regarded as confacial octahedral–trigonal prismatic. The six-membered MnO2P2N rings adopt a twisted-boat conformation. Although the distance between the metal centers, 3.160 A, is rather short, we discard a formal bonding interaction since the fragment Mn(CO)3 fulfills the 18e− rule with coordination to two oxygen atoms and a covalent interaction with a third oxygen atom.