Transition metal 1,3,2-diazagallol derivatives

Reduction of digallane (dpp-bian)Ga—Ga(dpp-bian) (1) (dpp-bian is the 1,2-bis[(2,6-di-isopropylphenyl)imino]acenaphthene dianion) with metallic sodium in THF leads to the formation of gallylsodium (dpp-bian)Ga—Na(thf)₄ (2). Reduction of digallane 1 with dicyclopentadienyltetracarbonyldiiron, vanadocene, and nickelocene furnishes the corresponding gallyl complexes (dpp-bian)Ga—FeCp(CO)₂ (3), (dpp-bian)Ga—VCp₂ (4) and [(dpp-bian)Ga]₂NiCp (5). The reaction of 1 with Cp₂Mn gives a gallium-free complex (dpp-bian)MnCp(dme) (6). Carbonylates [{(dpp-bian)Ga—M(CO)₅}{Na(thf)₂}]₂ (M = Cr (7), W (8)) and [{(dppbian)Ga}₂FeCp(CO)][Na(dme)₃] (9) were obtained by the reaction of carbonyls Cr(CO)₆, W(CO)₆, and [CpFe(CO)₂]₂ with compound 2. Diamagnetic derivatives 3, 7, 8, and 9 were characterized by ¹H NMR spectra. The structures of products 3—9 were established by single crystal X-ray diffraction.     

Europium and Ytterbium Complexes with the Redox Active Acenaphthene-1,2-Diimine Ligand

The oxidation of [(Dpp-Bian)Eu(Dme)₂] (I) (Dpp-Bian is the 1,2-bis[(2,6-diisopropylphenyl) imino]acenaphthene dianion, Dme = 1,2-dimethoxyethane), prepared in situ, with 0.5 mol equiv. of iodine in Thf gives europium(II) dimer, [(Dpp-Bian)Eu(μ-I)(Thf)₂]₂ (II) (Thf = tetrahydrofuran), with the Dpp-Bian ligand as radical anion. The exchange reaction of II with potassium dithiocarbamate affords europium( II) dimer, [(Dpp-Bian)Eu[SC(S)NMe₂](Thf)]₂ (III), which also contains the Dpp-Bian radical anion. However, the oxidation of the ytterbium complex [(Dpp-Bian)Yb(Dme)₂] (IV) with 0.5 mol equiv. of [Me₂NC(S)S]₂ gives the monomeric product [(Dpp-Bian)Yb[SC(S)NMe₂](Dme)] (V), in which Dpp-Bian is still the dianion and the ytterbium atom is oxidized to the trivalent state. The reaction of II with potassium thiocyanate gives europium(II) isothiocyanate complex with the radical anion diimine ligand [(Dpp-Bian)Eu(NCS)(Dme)₂] (VI). The molecular structures of complexes II, III, V, and VI were determined by X-ray diffraction (CIF files CCDC 1576687–1576690, respectively).     

Iron(II) complexes [Fe(DfgH)<Subscript>2</Subscript>(3-CONH<Subscript>2</Subscript>-Py)<Subscript>2</Subscript>] and [Fe(DfgH)<Subscript>2</Subscript>(4-COOC<Subscript>2</Subscript>H<Subscript>5</Subscript>-Py)<Subscript>2</Subscript>]: Synthesis and structures

The complexes [Fe(DfgH)₂(3-CONH₂-Py)₂] (I) and [Fe(DfgH)₂(4-COOC₂H₅-Py)₂] (II), where DfgH₂ is α-benzyl dioxime, were obtained and examined by X-ray diffraction analysis. The equatorial planes of the coordination octahedra of the metal ions consist of two monodeprotonated α-benzyl dioxime residues united through intramolecular hydrogen bonds O-H…O into a pseudomacrocyclic system. The neutral molecules 3-CONH₂-Py and 4-COOC₂H₅-Py are coordinated to the Fe²⁺ ion through the N atom of the heterocycle. Structure I is layered and structure II is molecular. Intermolecular interactions N-H…O are responsible for the formation of layers in crystal structure I.     

Tris(5-bromo-2-methoxyphenyl)bismuth dicarboxylates [(C<Subscript>6</Subscript>H<Subscript>3</Subscript>(Br-5)(MeO-2)]<Subscript>3</Subscript>Bi[OC(O)CHal<Subscript>3</Subscript>]<Subscript>2</Subscript> (Hal = F,Cl): synthesis and structure

Tris(5-bromo-2-methoxyphenyl)bismuth dicarboxylates [(C₆H₃(Br-5)(MeO-2)]₃Bi[OC(O)CHal₃]₂, Hal = F (II) and Cl (III), have been synthesized by the reaction between tris(5-bromo-2-methoxyphenyl)bismuth (I) and trifluoroacetic acid and thrichloroacetic acid, respectively, in the presence of hydrogen peroxide in ether. According to X-ray diffraction data, a crystal of complex I contains two types of crystallographically independent molecules (a and b) both with a trigonal pyramid configuration. The bismuth atoms in complexes II and III have a distorted trigonal bipyramidal coordination with carboxylate substituents in axial positions. Axial OBiO angles are 166.3(3)° (II) and 171.6(2)° (III); equatorial CBiC angles are 118.0(3)°–123.1(3)° (II) and 113.6(3)°–127.4(3)° (III). Bi–C bond lengths are 2.189(7)–2.200(8) Å (II) and 2.190(8)–2.219(7) Å (III), and Bi–О distances are 2.280(6), 2.459(16) Å (II) and 2.264(5), 2.266(5) Å (III). Intramolecular contacts between the central atom and the oxygen atoms of carbonyl groups (Bi···O 3.028(9), 3.162(9) Å (II); 3.117(9), 3.202(9) Å (III)) are observed at maximum equatorial angles. The oxygen atoms of methoxy groups are coordinated to the bismuth atom. The Bi···O distances in complexes II and III (3.028(16), 3.157(16), 3.162(16) and 3.17(16), 3.143(16), 3.202(16) Å, respectively) are slightly longer than in complex I (3.007(9)–3.136(4) Å).     

Syntheses and crystal structures of [Bi(DMSO)<Subscript>8</Subscript>][Fe(NCS)<Subscript>6</Subscript>] and [Al(DMSO)<Subscript>6</Subscript>][Al(NCS)<Subscript>6</Subscript>]

New complexes of composition [Bi(DMSO)₈][Fe(NCS)₆] (1) and [Al(DMSO)₆][Al(NCS)₆] (2) have been prepared, and an octahedral hexarodanoaluminate anion has been structurally characterized for the first time. Crystals of compound 1 are triclinic, space group \(P\bar 1\), a = 11.2368(4) Å, b = 11.4063(4) Å, c = 21.0711(9) Å, α = 92.9520(10)°, β = 99.9430(10)°, γ = 111.9290(10)°, V = 2447.69(16) ų, Z = 2, ρ_calc = 1.680 g/cm³, R ₁ = 0.0564; crystals of compound 2 are cubic, space group \(Pa\bar 3\), a = 15.8201(4) Å, V = 3959.39(17) ų, Z = 4, ρ_calc = 1.462 g/cm³, R ₁ = 0.0475. The bismuth coordination polyhedron BiO₈ in compound 1 is a distorted square antiprism with broken square faces (Bi-O, 2.368-2.582 Å). In the structure of 2, the cation disordered in a complex manner has an octahedral configuration (Al-O, 1.888(11)-1.912(11) Å).     

Binuclear bismuth halide complexes (<Emphasis Type="Italic">N</Emphasis>-Me(2,2'-BipyH))<Subscript>2</Subscript>[Bi<Subscript>2</Subscript>X<Subscript>10</Subscript>] (X = Cl,Br): Syntheses,crystal structures,and optical properties

Binuclear halide complexes (N-Me(2,2'-BipyH)₂[Bi₂X₁₀] (X = Cl (I), Br (II); 2,2'-Bipy = 2,2'-bipyridine) are synthesized by the reaction of solutions of [BiX₆]^3– and (N-Me(2,2'-BipyH)(NO₃)₂ in 2 M HX. The structure of [Bi₂X₁₀]^4– anions consists of octahedral fragments {BiX₆} linked by two μ₂-bridging halide ligands. The structures of the compounds are determined by X-ray diffraction analysis (CIF files CCDC 1455987 (I) and 1455988 (II)). The forbidden gap width E _g is determined for complex II from the diffuse reflectance spectrum.     

Synthesis and crystal structure of two complexes [Cu<Subscript>2</Subscript>(NiL)<Subscript>2</Subscript>Cl<Subscript>4</Subscript>] and [Cd<Subscript>2</Subscript>(CuL)<Subscript>2</Subscript>Cl<Subscript>4</Subscript>]

Macrocyclic and supermolecular complexes [Cu₂(NiL)₂Cl₄] (I) and [Cd₂(CuL)₂Cl₄] (II) (H₂L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-diene) have been synthesized and structurally determined by X-ray diffraction and IR spectrum. Complex I crystallizes in the monoclinic system with P2₁/n group, a = 10.9019(15), b = 14.3589(19), c = 12.4748(17) 0A, β = 108.645(2)°, Z = 4. Complex II crystallizes in the monoclinic system with P2₁/n group, a = 10.9784(16), b = 14.580(2), c = 12.8904(18) Å, β = 109.339(2)°, Z = 4.     

Crystal structures of triphenylamylphosphonium iodide [Ph<Subscript>3</Subscript>AmP]I and triphenylamylphosphonium tetraiodide [Ph<Subscript>3</Subscript>AmP]I<Subscript>4</Subscript>

By reaction of triphenylamylphosphonium iodide [Ph₃AmP]I (I) with antimony iodide in acetone, triphenylamylphosphonium tetraiodide [Ph₃AmP]₂I₄ (II) was synthesized. Crystals of I consist of triphenylamylphosphonium cations and iodine anions. Compound II contains two types of tetrahedral triphenylamylphosphonium cations, iodine anions, and [I₃]^? anions. Atoms P have a distorted tetrahedral coordination in cations I and II (the CPC angles are 106.48(12)°–111.25(12)° in I and 107.05(9)°–112.62(10)° in II). The centrosymmetric trinuclear [I₃]^? anion in II is nearly linear (the I(2)I(1)I(3) angle is 178.65°, the I(1)–I(2) and I(1)–I(3) bond lengths are 2.8925(2) Å and 2.9281(2) Å, respectively).     

Synthesis and X-ray investigation of Rb<Subscript>2</Subscript>[Pd(NO<Subscript>3</Subscript>)<Subscript>4</Subscript>] and Cs<Subscript>2</Subscript>[Pd(NO<Subscript>3</Subscript>)<Subscript>4</Subscript>]

Powder and single crystal X-ray diffraction studies have been performed for anhydrous nitrate complexes Rb₂[Pd(NO₃)₄] (I) and Cs₂[Pd(NO₃)₄] (II). Crystal data for I: a = 7.843(1) Å, b = 7.970(1) Å, c = 9.725(1) Å; β = 100.39(1)°, V = 597.9(1) Å ³, space group P2₁/c, Z = 2, d _calc = 2.918 g/cm³; for II: a = 10.309(2) Å, b = 10.426(2) Å, c = 11.839(2) Å; β = 108.17(3)°, V = 1209.0(4) ų, space group P2₁/c, Z = 4, d ^calc = 3.408 g/cm³. The structures are formed by isolated [Pd(NO₃)₄]^2? complex anions and alkali metal cations. The plane-square environment of the Pd atom is formed from the oxygen atoms of the monodentate nitrate groups. The geometrical characteristics of the complex anions are analyzed. Compound II has a short contact Pd...Cs 3.252 Å.     

Aluminum hydrides with radical-anionic and dianionic acenaphthene-1,2-diimine ligands

The reaction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) with LiAlH₄ affords two products regardless of the solvent used (tetrahydrofuran or diethyl ether). These products were isolated as green and colorless crystals. Green crystals of the complex [(dpp-bian)Al(H)₂Li(THF)₃] (1) were obtained from tetrahydrofuran; colorless crystals of the complex [{dpp-bian(H₂)}Al(H)₂Li(Et₂O)₂] (2), from diethyl ether. The reactions of compound 1 with 2,6-di-tert-butyl-4-methylphenol and benzophenone gave monohydrides [(dpp-bian)Al(H)(OC₆H₂-2,6-Bu₂ ^t-4-Me)][Li(THF)₄] (3) and [(dpp-bian)Al(H)(OCHPh₂)- Li(THF)₂] (4), respectively. The diamagnetic aluminum hydride [(dpp-bian)AlH(THF)] (5) was synthesized by the reaction of dichloroalane HAlCl₂ (in situ) with the disodium salt of dpp-bian in THF; the paramagnetic hydride [(dpp-bian)AlH(Cl)] (6) containing the dpp-bian radical anion was synthesized by the reaction of the monosodium salt (dpp-bian)Na with monochloroalane H₂AlCl (in situ) in diethyl ether. The reaction of compound 6 with tert-butyllithium gives the complex [(dpp-bian)AlBu^t(Et₂O)] (7). Diamagnetic derivatives 1—5 and 7 were characterized by ¹Н NMR spectroscopy; paramagnetic compound 6, by ESR spectroscopy. The molecular structures of compounds 1—7 were determined by single-crystal X-ray diffraction.     

Zinc(II) complexes of 4-aminoantipyrine (AAP). Crystal structure of [Zn(AAP)<Subscript>2</Subscript>Cl<Subscript>2</Subscript>]

Zinc(II) complexes of 4-aminoantipyrine (AAP), [Zn(AAP)₂X₂] (X = Cl^–, I^–) and [Zn(AAP)(CN)₂] · 2H₂O were prepared and characterized by elemental analysis, IR and NMR (¹H & ¹³C) spectroscopy. The crystal structure of [Zn(AAP)₂Cl₂] (1) was determined by X-ray crystallography. The structural analysis of 1 shows that the complex exists as a monomeric nonionic molecule with zinc atom bound to two AAP ligands and two chloride ions adopting a distorted tetrahedral geometry. In [Zn(AAP)₂(CN)₂] · 2H₂O, the appearance of a band at 2162 cm^–1 in IR and resonances around 142 ppm in the ¹³C NMR spectra indicated the binding of cyanide to zinc(II).     

Crystal structures of <Emphasis Type="Italic">trans</Emphasis>-[Re<Subscript>6</Subscript>S<Subscript>8</Subscript>(CN)<Subscript>2</Subscript>L<Subscript>4</Subscript>] complexes,L = pyridine or 4-methylpyridine

The structures of three novel octahedral rhenium cluster compounds [Re₆S₈(CN)₂(py)₄]·H₂O (1), [Re₆S₈(CN)₂(4-Mepy)₄] (2), [Re₆S₈(CN)₂(4-Mepy)₄]·4-Mepy (3) (py = pyridine, 4-Mepy = 4-methylpyridine) are determined by X-ray crystallography. Crystal data are: C2/m space group, a = 14.813(1) Å, b = 14.772(1) Å, c = 9.2122(6) Å, β = 119.085(2)°, V = 1761.7(2) ų, d _x = 3.318 g/cm³, R = 0.0585 (1); I4₁/amd space group, a = 16.0018(3) Å, c = 14.7186(5) Å, V = 3768.81(16) ų, d _x = 3.169 g/cm³, R = 0.0489 (2); P2₁/c space group, a = 9.0452(4) Å, b = 15.8065(7) Å, c = 15.2951(6) Å, β = 103.700(2)°, V = 2124.57(16) ų, d _x = 2.957 g/cm³, R = 0.0245 (3). Molecular cluster complexes interact via π-π stacking affording 3D frameworks in 1 and 2 and chains in 3.     

Synthesis,some properties,and crystalline modifications of <Emphasis Type="Italic">fac</Emphasis>-[Ru(NO)(Py)<Subscript>2</Subscript>Cl<Subscript>3</Subscript>]

According to the data of ¹H NMR spectroscopy, trans-hydroxochloro complexes containing from two to four pyridine molecules in the internal sphere are formed on the heating of a dilute aqueous solution of K₂[Ru(NO)Cl₅] with pyridine. The evaporation of the reaction solution with concentrated hydrochloric acid gives fac-[Ru(NO)(Py)₂Cl₃] (I) in a yield of ~90%. The structures of two crystalline modifications of this complex are determined by X-ray diffraction analysis (CIF files ССDС nos. 1452208 (Ia) and 1452207 (Ib)). IR spectroscopy shows that the irradiation of complex I (λ ~ 450 nm, T = 80 K) results in photoisomerization with the formation of the metastable state MS1 in which the nitroso group is coordinated by the oxygen atom. The activation parameters of the photoisomerization are determined from the data of differential scanning calorimetry (DSC). Compound trans-[Ru(NO)Py₄(OH)]Cl₂ ? H₂O is isolated in a yield of ~70% on reflux of complex I with a pyridine excess in an aqueous solution, and the presence of molecules of water of crystallization in this compound is confirmed by thermal gravimetry (TG) and IR spectroscopy.     

Three- and four-coordinated silver(I) ions in the coordination polymers [Ag(Me<Subscript>4</Subscript>Pyz)<Subscript>2</Subscript>]PF<Subscript>6</Subscript> and [Ag(2,3-Et<Subscript>2</Subscript>Pyz)<Subscript>2</Subscript>]PF<Subscript>6</Subscript>

The coordination polymers [AgPF₆(Me₄Pyz)₂] (I) and [AgPF₆(2,3-Et₂Pyz)₂] (II) were synthesized, and their structures were determined. Crystals of I are monoclinic, space group C2/c, a = 10.213(2) Å, b = 16.267(3) Å, c = 12.663(3) Å, β = 92.90(3)°, V = 2102.1(7) ų, ρ_calcd = 1.660 g/cm³, Z = 4. The structure of I is built of polymeric zigzag [Ag(C₈H₁₂N₂)] _∞ ⁺ chains and octahedral [PF₆] anions. The coordination polyhedron of the Ag⁺ ion is a flat triangle. Crystals of II are tetragonal, space group P \(\bar 4\)2(1)/c,a = b = 10.641(1) Å, c = 18.942(1) Å, V = 2144.6(2) ų, ρ_calcd = 1.627 g/cm³, Z = 4. In the structure of II, 2D cationic layers of fused square rings exist; the rings consist of four Ag⁺ cations linked by four bridging ligands of diethylpyrazine Et₂Pyz. The coordination polyhedron of the Ag⁺ ion is an irregular four-vertex polyhedron.     

1,3,2-Diazasilols based on 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene

Reduction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (1, dpp-bian) in the presence of SiCl₄ with two equivalents of potassium graphite (KC₈) in tetrahydrofuran leads to the formation of compound (dpp-bian)SiCl₂ (2), which was also synthesized by the exchange reaction of SiCl₄ with the magnesium complex (dpp-bian)Mg(THF)₃. An analog of compound 2, the bromo derivative (dpp-bian)SiBr₂ (3), was obtained by the reaction of SiBr4 with one equivalent of Na2(dpp-bian) (in situ from Na and dpp-bian) in toluene. The silylene (dpp-bian)Si (4) was synthesized by the reduction of a mixture of dpp-bian and SiCl₄ (1: 1) with four equivalents of potassium graphite in tetrahydrofuran. Treatment of compound 4 with diimine 1 gives the derivative (dpp-bian)₂Si (5). Compounds 2–5 were characterized by ¹H, ¹³C, and ²⁹Si NMR spectroscopy, as well as by elemental analysis, their molecular structure was established by X-ray diffraction studies.     

The activation of C-H bonds in C<Subscript>1</Subscript>-C<Subscript>3</Subscript> alkanes by zirconium(III,IV) and titanium(III,IV) hydrides immobilized on the surface of SiO<Subscript>2</Subscript>: a density functional theory study

Model reactions of the (≡Si-O-)₃M^IVH (1), (≡Si-O-)₂M^IVH₂ (2), and (≡Si-O-)₂M^IIIH (3) hydrides, where M = Ti and Zr, immobilized on the surface of silica with methane and propane were studied by the density functional theory with the PBE functional. The reactions involved the breaking of C-H alkane bonds and the formation of the (≡Si-O-)₃MR, (≡Si-O-)₂M(H)R, and (≡Si-O-)₂MR products (R = Me, n-Pr, and i-Pr), respectively. Reactions with the participation of 1 and 2 were found to occur as bimolecular processes without the formation of agostic-type prereaction complexes. With 3, the reaction was accompanied by the formation of stable prereaction and postreaction complexes. The conclusion was drawn that dihydrides 2 and trivalent metal hydrides 3 were much more reactive with respect to alkane C-H bonds than monohydrides 1. All the systems studied were characterized by low reaction regioselectivities.     

Crystal Structure of Tl<Subscript>2</Subscript>[NbCl<Subscript>6</Subscript>] and Tl<Subscript>2</Subscript>[NbBr<Subscript>6</Subscript>]

Single crystals of Tl₂[NbCl₆] (1) and Tl₂ [NbBr₆] (2) are obtained as black needles on heating TlCl, Nb, S₂Cl₂ (1) and Tl, Nb, and Br₂ at 400°C (2). Tl₂NbBr₆ also forms in the reaction of TlBr, Nb, Br₂, and S at 500°C. Both compounds crystallize in the K₂[PtCl₆] structure type to form non-distorted octahedral [NbХ₆]^2– anions (Nb–Cl 2.397(4) Å and Nb–Br 2.516(2) Å). The magnetic properties of Tl₂[NbBr₆] in a range 5-300 K indicate an antiferromagnetic interaction between Nb⁴⁺ ion spins (d¹, S = 1/2). On cooling, the compound becomes a noncollinear ferromagnet with T_c = 23 K.     

Synthesis,structural, spectral,thermal and comparative biological activity studies of [V<Subscript>2</Subscript>O<Subscript>2</Subscript>(SO<Subscript>4</Subscript>)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>6</Subscript>]

The hydrothermal reaction of a mixture of V₂O₅, VCl₃, 2,5-pyridinedicarboxylic acid and diluted H₂SO₄ for 68 h at 180°C gives a blue colored solution which yields prismatic blue crystals of IV ₂ ^IV O₂(SO₄)₂(H₂O)₆] (1) in 32% yield (based on V). Complex 1 was investigated by means of elemental analysis (C, H and S), TGA, FT-IR, manganometric titration, Single Crystal X-ray Diffraction Methods and also comparative antimicrobial activities. Crystal data for the compound: monoclinic space group P2₁/c and unit cell parameters are a = 7.3850(12) Å, b = 7.3990(7) Å, c = 12.229(2) Å, β = 108.976(12)° and Z = 2. Although structure of 1 as a natural mineral has been previously determined, this work covers new preparation method and full characterization of 1 along with comparison of antibacterial activity between 1 and the commercial vanadium(IV) oxide sulfate hydrate compounds, VOSO₄ · xH₂O (Riedel-de Haën and Alfa Aesar brand names). 1 was evaluated for the antimicrobial activity against gram-positive, gram-negative bacteria, yeasts and mould compared with the commercial VOSO₄ · xH₂O compounds. 1 showed weak activity against bacteria Bacillus cereus, Nocardia asteroides and yeast Candida albicans. A good antimicrobial activity was recorded against Cirtobacter freundii (15 mm). There are only a few reproducible well-defined vanadium(IV) starting materials to use for exploring the synthesis of new materials. VCl₄, VO(acac)₂, VOSO₄ · xH₂O and [V(IV)OSO₄(H₂O)₄] · SO₄ · [H₂N(C₂H₄)₂NH₂] are common starting materials for such applications. In addition to these compounds, 1 can be used as an oxovanadium precursor.     

Dynamic in situ solvothermal reactions between ZnX<Subscript>2</Subscript> (X = Cl,ClO<Subscript>4</Subscript>) and a heterocyclic disulfide

Solvothermal reactions of 2-ppds (2-ppds = di[4-(pyridin-2-yl)pyrimidinyl]disulfide) with ZnX₂ (X = Cl, ClO₄) in mixed CH₃OH–CH₂Cl₂ solvent have been investigated. To better understand these reactions, solution analysis was conducted in parallel with single-crystal X-ray diffraction analysis of the in situ generated coordination complexes. At 120 °C, solvothermal reaction of 2-ppds with ZnCl₂ resulted in a discrete mononuclear coordination complex formulated as [ZnCl₂(L1)] (1), in which the zwitterion L1 (1-methyl-4-(pyridin-2-yl)pyrimidin-1-ium-2-olate) was formed in situ from 2-ppds, and solution analyses based on TLC and ESI–MS further showed that the reaction solution also contains in situ transformed products of L2 (bis(4-(pyridin-2-yl)pyrimidin-2-yl)sulfane) and L3 (2-methoxy-4-(pyridin-2-yl)pyrimidine). At 90 °C, solvothermal reaction between 2-ppds and Zn(ClO₄)₂ led to a discrete mononuclear coordination complex formulated as [Zn(SH)(L2)]ClO₄ (2) that features a terminally bound –SH group, while the reaction solution was also found to contain a library of in situ reaction products of 2-ppds including L1, L2, L3 and L4 ((4-(pyridin-2-yl)pyrimidin-2-yl) 4-(pyridin-2-yl)pyrimidine-2-sulfonothioate). Thus, the heterocyclic disulfide 2-ppds is transformed in situ into various organic products in a series of reactions involving C–S/S–S bond cleavage.     

Synthesis and crystal structures of Schiff base oxovanadium(V) complexes [VO(Bhm)(OCH<Subscript>3</Subscript>)(CH<Subscript>3</Subscript>OH)] and [VO<Subscript>2</Subscript>(Bpp)]

Compound [VO(acac)₂] reacts with the Schiff bases N′-(5-bromo-2-hydroxybenzylidene)-2-hydroxy-3-methylbenzohydrazide (H₂Bhm) and 4-bromo-2-[(2-piperidin-1-ylethylimino)methyl]phenol (HBpp) in absolute methanol to give the oxovanadium(V) complexes [VO(Bhm)(OCH₃)(CH₃OH)] (I) and [VO₂(Bpp)] (II), respectively. Both complexes were characterized by elemental analysis, IR spectra, and single-crystal X-ray determination. The crystal of I crystallizes in the triclinic space group \(P\bar 1\) with a = 7.625(2), b = 11.240(3), c = 12.156(4) Å, α = 77.404(5)°, β = 75.770(4)°, γ = 79.922(5)°, V = 977.4(5) ų, Z = 2. The crystal of II crystallizes in the monoclinic space group P2/c with a = 26.760(3), b = 6.655(1), c = 17.570(2) Å, β = 100.335(2)°, V = 3078.2(7) ų, Z = 8. The V atom in I is in an octahedral coordination, and those in II are intervenient between square pyramidal and trigonal bipyramidal coordination.