Synthesis,Crystal and Molecular Structure of Cd2(sacch)4(Im)4

The title compound has been synthesized and its crystal structure determined at room temperature. Cd₂(Sacch)₄(Im)₄ F.W. = 1225.83, monoclinic. Space group: C2/c, Z = 4, a = 20.065(3) Å, b = 11.164(4) Å, c = 20.697(6) Å, β = 94.69(5)°, The coordination polyhedron of Cd(II) correspond to a five-coordinate trigonal-bipyramid. In the title complex, two of the saccharin groups act as monodentate ligands. The other two act as bidentate ligands. The two Cd(II) ions are bridged by the two bidentate saccharin groups and the distance is 4.75 Å.     

Synthesis,Characterization and Crystal Structure of Tetrabutylbis(4,5-dimethoxy-2-nitro benzoato)Distannoxane Dimer

Abstract  

Reaction of di-n-butyltin oxide with 4,5-dimethoxy-2-nitrobenzoic acid yields the title compound which crystallizes as the usual dicarboxylatotetraorganodistannoxane dimer. Experimental details for the preparation and the structural characterization (by FTIR, NMR and single crystal XRD) are provided. The IR data shows that ligand acts in the bidentate manner. The crystal structure analysis of the compound reveals the presence of a centrosymmetric planar Sn₂O₂ unit connected to exocyclic Sn atom via two bidentate bridging carboxylate ligands. The remaining two carboxylate ligands are coordinated to the exocyclic Sn atom in the monodentate manner.     

Molecular Structure of [Cu<Subscript>2</Subscript>(MeCN)<Subscript>2</Subscript>(μ-tpy)<Subscript>2</Subscript>][BPh<Subscript>4</Subscript>]<Subscript>2</Subscript>: A Helical Di-Cuprous Terpyridine Complex

Abstract  The molecular structure of [Cu₂(MeCN)₂(μ-tpy)₂][BPh₄]₂ has been determined. The two terpyridine ligands coordinate to the same Cu(I) center in a bidentate configuration, in which the copper adopted a distorted tetrahedral geometry with the four nitrogen donors. The third ring of each terpyridine ligand forms a bridge with a second Cu(I) center, whose tetrahedral coordination sphere is completed by two acetonitrile ligands. The resulting structure represents a section of a double helix. Crystal data: space group C2/c, a = 27.202(5), b = 12.995(3), c = 23.409(5) ?, β = 123.13(3)°; V = 6930(2) ?³, Z = 4, R = 0.0613, wR ₂ = 0.0946. Graphical Abstract  The molecular structure of [Cu₂(MeCN)₂(μ-tpy)₂][BPh₄]₂ has been determined. The terpyridine ligands coordinate in a bidentate fashion to the same Cu center and monodentate to a second Cu center resulting in a double helical structural motif.      

Crystal structures of mixed ligand complexes containing saccharinate and nicotinamide: [Cu(saccharinato)2 (nicotinamide) (H2O)]⋅(H2O) and [M(nicotinamide)2 (H2O)4]⋅(saccharinate)2 (M = Ni2+, Co2+)

[M(saccharinato)₂(H₂O)₄] (M = Cu²⁺, Ni²⁺, Co²⁺) react with nicotinamide to form mixed ligand complexes, [Cu(saccharinato)₂(nicotinamide)(H₂O)](H₂O) (1) and [M(nicotinamide)₂(H₂O)₄](saccharinate)₂ (2: M = Ni²⁺; 3: M = Co²⁺), and their crystal structures have been determined by X-ray diffraction. In 1, the Cu²⁺ atom in an octahedral configuration is coordinated by two monodentate saccharinato ligands in the trans arrangement through the deprotonated ring nitrogens, by two bidentate nicotinamide ligands, one through the pyridyl ring nitrogen and the other through the amide oxygen, and by a water molecule, thus forming a nicotinamide-bridged one-dimensional extended structure. In the isomorphous complexes 2 and 3, the octahedral metal atom, which rides on a crystallographic center of symmetry, is coordinated by two monodentate nicotinamide ligands through the ring nitrogens and four water molecules to form a discrete [M(nicotinamide)₂(H₂O)₄]^{2 +} structural unit, which captures up and down two saccharinate ions, each through three hydrogen bonds: two hydrogen bonds between two water ligands and the ring N and the carbonyl O atoms and one between the amide N of the nicotinamide ligand and the carbonyl O.     

Crystal Structure and Physical Characterisation of [Zn<Subscript>2</Subscript>(Benzoato)<Subscript>4</Subscript>(Caffeine)<Subscript>2</Subscript>]·2 Caffeine

Abstract  

The crystal structure of [Zn₂(benzoato)₄(caffeine)₂]·(caffeine)₂ was determined by direct method and Fourier technique. The structure was refined by full-matrix least-squares method to a weighted R factor of 0.0582. The structure consists of centrosymmetric dimeric units where the two zinc(II) atoms are coordinated by four bridging benzoates in a syn–syn arrangement and two caffeine ligands at the apices of a bicapped square prism. Remaining two caffeines are bound only by hydrogen bonds. The Zn–Zn distance is 2.961(1) ?. The Zn(II) atoms are displaced by 0.365 ? from the basal plane containing four oxygen atoms towards the apical caffeine molecules. The dimeric structure of the complex is consistent with spectrum and thermal data. The structural data are compared with those found in similar [Zn₂(RCOO)₄(NL)₂] complexes.     

Synthesis and Crystal Structure of a New Dinuclear Holmium(III) Complex with a Bulky Anthracene-Based Carboxylate Ligand

Abstract  

The reaction of Ho(NO₃)₃ with the bulky anthracene-9-carboxylic acid (HL) and 1,10-phenanthroline (phen) in the presence of 2,6-dimethylpyridine afforded a dinuclear Ho^III complex [Ho₂(L)₆(phen)₂] (1) (L = anthracene-9-carboxylate), which was characterized by elemental analysis and single-crystal X-ray diffraction analysis (triclinic system, space group Pī, with a = 12.4994(3), b = 13.3556(3), c = 14.9751(3) ?, α = 110.7630(1), β = 103.0680(1), γ = 106.8530(1)°, V = 2080.59(9) ?³, and Z = 1). Complex 1 has a centrosymmetric binuclear cage structure in which two Ho^III atoms are both nine-coordinated and bridged by four bulky anthracnene-9-carboxylate (L) ligands with a non-bonding Ho∙∙∙Ho separation of 3.9076 (2) ?. The anthracene-9-carboxylate groups coordinate each Ho^III atom in three different ways. The adjacent discrete dinuclear subunits are arranged into a one-dimensional (1D) chain along the [111] direction by intermolecular π···π stacking interactions, with the centroid–centroid separation of 3.724(2) ?.     

The crystal structure and thermal stability of [bis-picrate(pentaethylene glycol)] praseodymium(III)picrate complex

[Bis-picrate(pentaethylene glycol)]praseodymium(III) picrate, [Pr(pic)₂⋅(EO5]⁺[pic]⁻, was successfully obtained from the reaction of praseodymium nitrate hexahydrate, picric acid and pentaethylene glycol in acetonitrile–methanol as solvent. The crystal system is monoclinic with space group P2₁/c, a = 18.91419(11) Å, b = 9.0470(6) Å, c = 24.1209(14) Å and α = γ = 90^∘, β = 109.07(1)^∘, V = 3880.3(4) ų and Z = 4. The Pr atom is coordinated to the flexible and open EO5 ring via all the six oxygen atoms and two picrate ligands, one via phenoxo oxygen atom and the other one with both phenoxo and nitro oxygen atoms in a bidentate manner resulting a 9-coordinate tricapped trigonal prismatic geometry. The two picrate ligands coordinated to the Pr atom are at the opposite sides of the hexadentate EO5 ring with phenyl fragments almost perpendicular with dihedral angle of 89.7(3)^∘. Thermal analysis results show that the complex is stable up to 100^∘C when it began to slowly decompose and followed by an explosive decomposition at 290^∘C.     

Synthesis and crystal structure of oxonitrate complexes Cs[VO2(NO3)2], Cs[MoO2(NO3)3], and MoO2(NO3)2

Cs[VO₂(NO₃)₂] (I), MoO₂(NO₃)₂ (II), and Cs[MoO₂(NO₃)₃] (III) complexes have been obtained by crystallization from nitric solutions and studied by single-crystal X-ray diffraction. Complexes I and II contain infinite zigzag chains of similar compositions, [VO₂(NO₃)₂]⁻ and [MoO₂(NO₃)₂], in which V and Mo atoms form, respectively, trigonal- and pentagonal-bipyramidal polyhedra. Each of these polyhedrons also contains one terminal and two bridge O atoms and two terminal NO₃ groups which are monodentate and bidentate in complexes I and II, respectively. Complex III has an island structure and consists of Cs⁺ cations and [MoO₂(NO₃)₃]⁻ anions, in which the Mo atom is surrounded by one bidentate NO₃ group and two monodentate NO₃ groups and two terminal O atoms in the cis-positions; oxygen atoms form a polyhedron in the form of distorted octahedron. According to the ab initio calculation of isolated MoO₂(NO₃)₂ molecules in the gas phase and solution, the coordination environment of the Mo atom, similarly to the Cr(VI) atom in CrO₂(NO₃)₂, is formed by two bidentate nitrate groups and two terminal O atoms (polyhedron- twisted trigonal prism).     

Synthesis,characterization, and structure of lanthanide picrate complexes with tetramethylenesulfoxide (TMSO)

A series of complexes with composition M(pic)₃(TMSO)₃ (M=La, Nd, Sm, Eu, Gd, Er, Yb, and Y) were synthesized and characterized. The electronic absorption spectrum of the Nd complex and the emission spectrum of the Eu complex were recorded and assigned. The unique compound, Sm(pic)₃(TMSO)_2.5(EtOH)_0.5, obtained by recrystallizatiori of Sm(pic)₃(TMSO)₃ from ethanol, was characterized by single-crystal X-ray analysis. The complex crystallizes in a monoclinic cell space groupP2₁/n witha=21.809(4)Å,b=15.811(3)Å,c=12.800(3)Å and =99.87(4)°. The coordination polyhedron about the Sm center is a tricapped trigonal prism involving the three picrates, which act as bidentate ligands via the phenoxo oxygen and an oxygen of an adjacent nitro group, as well as the oxygens of two TMSO ligands. The ninth position is statistically (50%) occupied by an oxygen atom of a third TMSO ligand and an oxygen atom of an ethanol molecule.     

Synthesis,Crystal Structure and IR Spectra of Complexes of Mn(II) by Indole-2-Carboxylic or Isoquinoline-1-Carboxylic Acids and 1,10-Phenanthroline

Abstract  

Two ternary complexes of manganese(II) indole-2-carboxylate (2-IC⁻) or isoquinolinecarboxylate (IQC⁻) with 1,10-phenanthroline (phen) in methanol or in dimethylacetamide (DMA) were synthesized and studied by X-ray diffraction and IR spectra. [Mn(C₉H₆NO₂)₂(C₁₂H₈N₂)₂]·CH₄O (1) crystallizes in the triclinic space group P-1 with cell parameters of a = 10.548(2) ?, b = 14.168(3) ?, c = 14.580(3) ?, α = 62.35(2)°, β = 69.16(2)°, γ = 78.61(2)°, V = 1802.4(6) ?³ and Z = 2; [Mn(C₁₀H₆NO₂)₂(C₁₂H₈N₂)].C₄H₉NO (2) crystallizes in the monoclinic space group P2₁/a with cell parameters of a = 15.304(5) ?, b = 12.871(5) ?, c = 17.421(5) ?, β = 114.39(1), V = 3125(2) ?³ and Z = 4. In 1, Mn is six-coordinate by two bidentate phen ligands and two 2-IC⁻ ligands and exhibits a very distorted octahedral geometry. This complex is solvated by methanol involved in hydrogen bonding. In 2, Mn atom is surrounded by one bidentate phen ligand and two bidentate IQC⁻ ligands. The complex exhibits a distorted octahedral geometry around the Mn^II atom. The crystal structure is completed by a disordered DMA solvate molecule. The IR spectra of both compounds are slightly different in the range 4000–2400 cm⁻¹ which may be attributed to hydrogen bond lack in 2.     

Self-Assembled Hydrogen-Bonding Chains of Copper(II) 2-Nitrobenzoate with Nicotinamide

Abstract  

The synthesis, spectral characterization and crystal structure of two new nitrobenzoatocopper(II) complexes, namely, [Cu₂(2-O₂Nbz)₄(nia)₂]·ACN (1) and [Cu₂(2-O₂Nbz)₄(ACN)₂] (2) (where 2-O₂Nbz = 2-nitrobenzoate, nia = nicotinamide and ACN = acetonitrile) are reported. The complexes 1 and 2 form dinuclear units of the paddle-wheel type around the crystallographic inversion centers. The copper ions are bridged by four 2-nitrobenzoate anions and the neutral N-donor ligands, viz. nicotinamide in 1 and acetonitrile in 2, are coordinated at apical positions. Selected geometric parameters of both complexes are compared with values for related tetra-2-nitrobenzoate complexes of copper(II) as well as the other dimeric copper(II) carboxylates with apical nicotinamide and acetonitrile ligands. The molecules of 1 are linked with N–H···O and C–H···O hydrogen bonds. The π–π stacking interactions in 1 are observed between benzene rings of 2-nitrobenzoate anions and pyridine rings of nicotinamide and also between acetonitrile molecules and benzene rings of 2-nitrobenzoate anions. The C–H···O hydrogen-bonds and CH/π interactions are observed in crystal structure of 2.     

Synthesis and Properties of a New Kind of One-Dimensional Conductors 17. Studies on monomeric and polymeric phthalocyaninato-iron(II) and -cobalt(II) complexes

A new approach for a one-dimensional organic conductor with a chemically bonded backbone is presented. The proposed compounds consist of a linear arrangement of transition metal atoms, e.g. Fe, Co, bridged by linear bidentate π-electron containing ligands, e.g. pyrazine, 4,4'-bipyridine, and 1,4-diisocyanobenzene. This structure is stabilized by the tetradentate planar phthalocyanine molecule complexing each octahedrally coordinated central atom in its equatorial plane. The synthesis and characterization of the monomeric, dimeric and polymeric compounds PcML/PcML₂, PcM-L-PcM and [PcML]_n are described and a comparison of their electrical conductivity as a function of their structural features is given in detail. The electrical conduction of the monomeric units increases after polymerisation by a factor of 10⁷ without doping. In the second part soluble tetrasubstituted phthalocyaninato(IVB)-metalloxanes are described and the effect of homogeneous and heterogeneous iodination on conductivity is discussed.     

Synthesis and crystal structures of quadruply carboxylate-bridged dimeric lanthanide(III) complexes of betaine

Three dimeric lanthanide(III) complexes, [Eu₂(bet)₈(H₂O)₄](CIO₄)₆ (1), [Tb₂(bet)₈(H₂O)₄](ClO₄)₆ (2), and [Eu₂(bet)₄(H₂O)₈] Cl₆·6H₂O (3) (bet = Me₃N⁺CH₂COO^–, trimethyl-aminoacetate), have been prepared and structurally characterized by X-ray crystallography. Complex 1 crystallizes in the monoclinic space group P2₁/c, with a = 11.7807(8), b = 27.757(5), c = 11.7980(8) Å, = 99.500(4)°, V = 3805.1(8) ų, and Z = 2. Complex 2 is isomorphous to complex 1, crystallizing in the monoclinic space group P2₁/c, with a = 11.7769(14), b = 27.725(3), c = 11.795(5) Å, = 99.668(14)°, V = 3797(2) ų, and Z = 2. Complex 3 crystallizes in the orthorhombic space group Pbca, with a = 12.5664(8), b = 17.8645(9), c = 22.2573(8) Å, V = 4996.6(4) ų and Z = 4. Both complexes 1 and 2 comprise quadruply carboxylate-O,O-bridged [M₂(bet)₄]⁶⁺ dimeric cores (M = Eu, Tb), and each metal ion is further coordinated by two terminal aqua ligands and two monodentate bet carboxylates to form a distorted square-antiprismatic coordination geometry. Complex 3 also has a [Eu₂(bet)₄]⁶⁺ core, in which two bet ligands act in the ¹:¹:₂ bridging fashion, and the other two bet ligands in the less common ²:¹:₂ bridging fashion, namely bridging-chelate mode. Each europium(III) ion in complex 3 is further coordinated by four water molecules to complete a monocapped square antiprism.     

Synthesis and crystal structure of the [Co<Subscript>2</Subscript>(Nicotinamide)<Subscript>4</Subscript>(C<Subscript>4</Subscript>H<Subscript>9</Subscript>COO)<Subscript>4</Subscript>(H<Subscript>2</Subscript>O)] complex

The [Co₂ L ₄(C₄H₉COO)₄(H₂O)] coordination compound of cobalt(II) valerate with nicotinamide (L) is synthesized and studied by IR spectroscopy. The crystal structure of the synthesized compound is determined. The crystals are triclinic, and the unit cell parameters are as follows: a = 10.2759(10) Å, b = 16.3858(10) Å, c = 16.4262(10) Å, α = 100.538(10)°, β = 101.199(10)°, γ = 90.813 (10)°, Z = 2, and space group P \(\bar 1\). The structural units of the crystal are dimeric molecular complexes in which pairs of cobalt atoms are linked by triple bridges formed by oxygen atoms of two bidentately coordinated valerate anions and a water molecule. The octahedral coordination of each cobalt atom is complemented by the pyridine nitrogen atoms of two nicotinamide ligands and the oxygen atom of the monodentate valerate group. The hydrocarbon chains of the valerate anions are disordered over two or three positions each.     

Synthesis, Crystal Structure and Properties of the Binuclear Complex [Sm2(C10H9N2O4)2(C10H8N2O4)2(H2O)4]

Abstract  A novel binuclear Smarium (III) complex with N-(2-propionic acid)-salicyloyl hydrazone (C₁₀H₁₀N₂O₄, H₃L) was prepared and characterized. The crystal structure of [Sm₂(H₂L)₂(HL)₂(H₂O)₄] (1) was determined by X-ray single crystal diffractometry. 1 crystallizes in the monoclinic systerm, space group P2(1)/c, with a = 0.10229(2), c = 31.549(7), b = 0.70599(15) nm, and Z = 4. In the structure, Sm(III) is nine-coordinated by carboxyl O and acyl O atoms and imido N atoms of two ligands (H₂L and HL forms) and O atoms from two water molecules. H₂L and HL act as tridentate ligands which form two stable five-numbered chelating rings sharing one edge in the keto form for each ligand, and the carboxyl groups of two ligands were coordinated via bidentated bridging form. The coordination polyhedron around Sm (III) was described as a monocapped square antiprism. The inter- and intramolecular hydrogen bonds resulted in a three-dimensional network and provided extra stability for the structure. The complex was researched the interaction with calf thymus DNA by electronic absorption titration and emission titration. The results show that the complex is bound to calf thymus DNA mainly by intercalation .The complex also shows good fluorescence property. Index Abstract  The title compound, [Sm₂(H₂L)₂(HL)₂(H₂O)₄] was synthesized by the treatment of N-(2-propionic acid)-salicyloyl hydrazone (C₁₀H₁₀N₂O₄, H₃L) and Sm(NO₃) · 4H₂O and its crystal structure determined. Single crystal X-ray diffraction analysis reveals that Sm (III) is nine-coordinated by carboxyl O and acyl O atoms and imido N atoms of two ligands (H₂L and HL forms) and O atoms from two water molecules. The carboxyl groups of two ligands were coordinated via bidentated bridging form. The coordination polyhedron around Sm (III) was described as a monocapped square antiprism. The inter- and intramolecular hydrogen bonds resulted in a three-dimensional network and provided extra stability for the structure.      

Synthesis and crystal structure of a polymeric erbium(III)–sodium(I) coordination complex of picolinic acid N-oxide

A new Er(III)–Na(I) coordination polymer of stoichiometry [NaEr₂L₅(H₂O)₆(NO₃)](NO₃)·3.5H₂O (HL = picolinic acid N-oxide) has been synthesized and characterized by single-crystal X-ray analysis. Crystals are triclinic, P with a = 9.823(2), b = 12.453(2), c = 20.643(4) Å; = 98.49(3), ( = 101.40(3), = 108.69(3)°; V = 2284(1) ų; Z = 2. Of the two independent eight-coordinate erbium(III) ions in this complex, one is surrounded by four bidentate chelating L ligands, and the other by one bidentate chelating L ligand, four aqua ligands and two anti-carboxylate oxygen atoms from two neighboring [ErL₄] units. The sodium(I) ion is in a distorted octahedral environment, being coordinated by a unidentate nitrate anion, three aqua ligands and two anti-carboxylate oxygen atoms from two adjacent [ErL₄] units. The complex is built from zigzag chains of syn-anti carboxylate-bridged erbium(III) moieties directed in the a direction, which are cross-linked pairwise by aqua-bridgeddimericsodium(I) units. The resulting composite polymeric chains are further connected by hydrogen bonds to form a three-dimensional network.     

Synthesis and Crystal Structures of Two Complexes with Carboxylic Derivatives of Nitrogen-containing Heterocycle Ligands

Abstract  

Two new complexes [Zn(pcn)₂(H₂O)₂] (1) and [Cd(inic)₂(H₂O)₄] (2) (pcn = 2-pyrazinecarboxylate, inic = isonicotinic acid) were synthesized by the hydrothermal reaction and characterized by single crystal X-ray diffraction, elemental analysis, IR spectrum and UV spectrum. In complex 1, the Zn(II) central ion is six-coordinated by two oxygen atoms and two nitrogen atoms from pcn ligands and two oxygen atoms from two coordinated water molecules. In complex 2, the Cd(II) central ion is six-coordinated by two nitrogen atoms from isonicotinate ligands and four oxygen atoms from the coordinated water molecules. Both complexes are mononuclear but hydrogen bonds enrich the structural construction. The visible spectra of the complexes between 200 and 300 nm are assigned to intraligand (IL) π–π* transitions of the pyridyl or pyrazine ligands.     

Synthesis,Structure and Luminescent Property of a Novel Lanthanide Metal-Organic Coordination Polymer Yb<Subscript>3</Subscript>(BDC)<Subscript>4.5</Subscript>(DMF)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>3</Subscript> · (DMF)<Subscript>2</Subscript>

Abstract  A three-dimensional lanthanide metal-organic coordination polymer Yb₃(BDC)_4.5(DMF)₂(H₂O)₃ · (DMF)₂ has been synthesized by the reaction of the lanthanide metal ion (Yb³⁺) with 1,4-benzenedicarboxylic acid (H₂BDC) under mild condition. The compound crystallizes in the triclinic system, space group PI with unit cell parameters a = 10.7428(9) Å, b = 11.2786(9) Å, c = 26.172(2) Å, α = 85.060(2)°, β = 88.1060(10)°, γ = 62.3670(10)°, V = 2798.9 (4) ų, Z = 2. The crystal structure exhibits one-dimensional channels along the [011] direction. The fluorescent results showed that there were two emission peaks at 375 and 420 nm when the compound was excited by a 235 nm excitation. Graphical Abstract  The preparation, X-ray structure and luminescent property are presented for a new lanthanide metal-organic coordination polymer Yb₃(BDC)_4.5(DMF)₂(H₂O)₃ · (DMF)₂.      

Reaction of (<Emphasis Type="Italic">n</Emphasis>-Bu<Subscript>4</Subscript>N)<Subscript>2</Subscript>[Re<Subscript>2</Subscript>Cl<Subscript>8</Subscript>] with a 2-Oxocarboxylic Acid: Crystallographic Characterization of a New Dirhenate(III) Complex

Abstract  

The reaction of tetra-n-butylammonium-octachloridodirhenate(III), (Bu₄N)₂[Re₂Cl₈], with molten 2-oxobutanoic acid Et(CO)CO₂H at 75 °C afforded pale-green tetra-n-butylammonium-hexachlorido-(2-oxobutanoato)-dirhenate(III), (Bu₄N)[Re₂(O₂C(CO)Et)Cl₆]. Slow evaporation of a solution in CHCl₃ yielded shiny, mint-green crystals of the dirhenate complex. The X-ray crystal structure determination (monoclinic, P2₁/n, a = 11.6557(3) ?, b = 20.5382(5) ?, c = 13.9281(3) ?, β = 112.508(1)°, Z = 4) revealed the presence of [Re₂(O₂C(CO)Et)Cl₆]⁻ anions and tetra-n-butylammonium cations. The central [Re₂]⁶⁺ core with a Re≣Re quadruple bond of 2.2263(3) ? length is μ₂-bridged by one 2-oxobutanoato ligand and additionally coordinated by six chlorido ligands. Each dirhenate unit is linked via two Re···Cl contacts to dimeric, centrosymmetric entities of the constitution {[Re₂(O₂C(CO)Et)Cl₆]₂}²⁻. In the crystal, these dimers of dinuclear complexes are separated from each other by the bulky tetra-n-butylammonium cations.     

The Crystal Structure of {[Pt(9S3)Cl<Subscript>2</Subscript>]<Subscript>2</Subscript>[Pt(9S3)<Subscript>2</Subscript>]}Cl<Subscript>2</Subscript>·4H<Subscript>2</Subscript>O: An Improved Synthesis of [Pt(9S3)Cl<Subscript>2</Subscript>]

Abstract  

We wish to report the crystal structure for a solid-state solution, {[Pt(9S3)Cl₂]₂[Pt(9S3)₂]}Cl₂·4H₂O (1), which contains two different complexes of Pt(II) with the trithiacrown 9S3 (1,4,7-trithiacyclononane). One complex [Pt(9S3)Cl₂] is neutral and contains a Pt(II) center with a single 9S3 ligand and two coordinated chloro ligands. The second Pt(II) complex is a dication and contains two coordinated 9S3 ligands and two non-coordinating chloride anions. There are two crystallographically equivalent [Pt(9S3)Cl₂] complexes present for every single [Pt(9S3)₂]²⁺ cation. Four water solvent molecules are also present. In the neutral complex ([Pt(9S3)Cl₂], the Pt(II) center is surrounded by a cis-[S₂Cl₂ + S₁] ligand environment formed by the two chloro ligands and two of the three sulfur atoms from the 9S3 ligand. These two sulfurs are positioned 2.225(2) and 2.242(2) ? from the Pt(II), but the third sulfur shows a long distance interaction at 3.311(2) ? to form an elongated square pyramidal structure. This axial Pt–S distance is the longest observed in 57 crystal structures of Pt(II) 9S3 complexes. The cation [Pt(9S3)₂]²⁺ displays two centrosymmetrically coordinated 9S3 ligands forming a [S₄ + S₂] environment with an elongated octahedral shape. In the dication, the two equatorial Pt–S distances are 2.297(2) and 2.306(2) ? with the axial sulfur at 3.065(2) ?. The most interesting intermolecular aspects of the structure are hydrogen bonding interactions between two of the water molecules and two chloride counter-ions, resulting in a nearly square O₂Cl₂ ring. This ring shares an edge with a six-membered ring formed by four waters and two chlorides which are hydrogen bonded. The hydrogen bonding interactions, which result from the presence of water in the crystal, appear to be an important component in stabilizing the lattice for the unusual solid-state solution structure. Crystal Data for (1): P2 ₁ /n, a = 7.8327(10) ?, b = 25.152(4) ?, c = 12.382(2) ?, V = 2314.3(6) ?³, Z = 2. We also report an improved synthetic procedure for the preparation of two thiacrown complexes [Pt(9S3)Cl₂] and [Pt(10S3)Cl₂], which are commonly used as precursors for other heteroleptic thioether complexes. The new syntheses proceed at room temperature without the need for long reflux times and produce large crystals which are easily isolable without filtration. The simplicity of these new preparations results in improved yields over previously employed methods.