A new series of potentially hexadentate ligands derived from 2,2′-bipyridine

Reaction of 2,2′-bipyridine-6-carboxaldehyde with the appropriate aliphatic diamine in MeOH and subsequent reduction with NaBH₄ gives the new, potentially hexadentate, ligands N,N′-bis(2,2′-bipyridin-6-ylmethyl)ethane-1,2-diamine (bmet), N,N′-bis(2,2′-bipyridin-6-ylmethyl)propane-1,3-diamine (bmpp) and N,N′-bis(2,2′-bipyridin-6-ylmethyl)hexane-1,6-diamine (bmhx). The syntheses and characterisation of these ligands are reported; the ligands are isolated as the hydrochloride salts, with purification effected by either recrystallisation or cation exchange chromatography. [Co(bmet)](ClO₄)₃ · H₂O is obtained on reaction of bmet · 4.25HCl · 2.5H₂O with Na₃[Co(O₂CO)₃] · 3H₂O, and X-ray structural analysis shows this to have a pair of very short Co–N bonds. The synthesis and characterisation of the first coordination complex containing 6-(aminomethyl)-2,2′-bipyridine (amb) is also described.     

Transition metal complexes with Girard reagent-based ligands. Part IV. Synthesis and characterization of pyridoxilidene Girard-T hydrazone complexes. Crystal structure of the copper(II) complex

Abstract  The monoligand complexes of the formula M(HPLGT)(NCS)₂ (M = Cu(II), Zn(II)) in which the ligand tridentate ONO pyridoxilidene Girard-T hydrazone, [H₃PLGT]Cl₂ · 2H₂O, was coordinated in neutral doubly deprotonated form were synthesized. Also, the first complexes with the ligand coordinated in triply deprotonated monoanionic form of the formula [Cu(PLGT)N₃] and [Co(PLGT)(NO₂)₂NH₃] · 3H₂O are reported. The single crystal X-ray analysis of [Cu(HPLGT)(NCS)₂] showed that Cu(II) is placed in a square-pyramidal surrounding consisting of one tridentate Schiff base and one NCS group in the basal plane and the other NCS group in the apical position. Intermolecular hydrogen bonds leading to centrosymmetrical dimerization of these complexes were discussed. In the reaction of Girard-T and Hacac in the presence of CuCl₂, a mixture of single crystal complexes of the composition [Cu(3,5-Me₂pz)₂Cl₂]₂ and [Cu(acac)₂] · 2[Cu(3,5-Me₂pz)₂Cl₂] was obtained and X-ray analysis of the latter one was reported. Index abstract  Crystal structure of the Cu(II) complex with pyridoxilidene Girard-T hydrazone was analyzed. Additional two Cu(II) complexes obtained by the reaction of Girard-T reagent and Hacac in the presence of CuCl₂ were also studied by single crystal X-ray analysis.      

Three new coordination complexes of cobalt(III), manganese(II), and copper(II) with N,N,O-donor hydrazone ligands: syntheses and structural characterizations

Three new coordination complexes, 2{[Co(L¹)₂]ClO₄} · 0.5CH₃OH (1), [Mn(L²)₂] (2), and [Cu(HL²)(L²)]ClO₄ · 2H₂O (3) have been synthesized from two tridentate N,N,O-donor hydrazone ligands HL¹, 2-acetylpyridine-salicyloylhydrazone, and HL², 2-benzoylpyridine-salicyloylhydrazone, respectively and thoroughly characterized by elemental analysis, FT-IR, UV–Vis, electrochemical, and room temperature magnetic susceptibility measurements. Structures of the complexes have been unequivocally established by single crystal X-ray diffraction technique. Structural analysis reveals that 1 consists of two chemically similar but crystallographically independent cationic [Co(L¹)₂]⁺ units and 2 consists of a neutral [Mn(L²)₂] molecule while 3 consists of a cationic [Cu(HL²)(L²)]⁺ unit. Metal ions display distorted octahedral geometry in 1 and 2 while in 3 it shows a distorted square pyramidal geometry. Ligand conformations around the metal ions are stabilized by the presence of intra-ligand hydrogen bonding in all the complexes. Structure of 3 reveals that a perchlorate ion linked to the complex by hydrogen bonding via a water molecule.     

Ketiminate supported aluminum(III) complexes: Synthesis, characterization and reactivity

The reaction of LLi, (L = [RNC(Me)CHC(Me) = O] (R = C₂H₄NEt₂)), with AlCl₃ at −78 °C forms the mono-ketiminate product, LAlCl₂, 1, while the same reaction at 0 °C affords the bis-ketiminate complex, [{(LH)₂AlCl}(Cl₂)], 2, Reduction of 1 with Li^o, K^o or Mg^o yielded an unusual dimeric aluminum(III) species, [L′AlCl]₂, 3, where C-C coupling of the ligand backbone is observed.     

Synthesis and Physicochemical Characteristics of New Tetrachloroferrates(III) with Dimethylammonium Cation: X‐ray Crystal Structure of Bis(dimethylammonium) Chloride Tetrachloroferrate(III)

Two new tetrachloroferrates(III) have been synthesized of molecular formulas [(CH₃)₂NH₂][FeCl₄] and [(CH₃)₂NH₂]₂FeCl₅. The differences in their physicochemical properties have been highlighted using thermal analysis (TG‐MS) and differential scanning calorimetry (DSC). The crystal and molecular structure of [(CH₃)₂NH]₂FeCl₅ was determined. The iron(III) cation is four coordinated by chloride ions, and it adopts a slightly distorted tetrahedral coordination with three angles smaller and three larger than the tetrahedral one. In the structure four intermolecular N‐H···Cl hydrogen bonds link the [(CH₃)₂NH₂]⁺ cations to dimers via a Cl^? bridge.     

Synthesis,crystal structures,and characterization of two Co(II) coordination polymers with 3-pyrid-3-ylbenzoic acid

Two pyridinecarboxylato-bridged coordination polymers {[Co(pbc)₂(H₂O)] · H₂O} _n (1) and [Co(pbc)₂] _n (2) (Hpbc = 3-pyrid-3-ylbenzoic acid) have been synthesized by the hydrothermal method and characterized by X-ray single crystal diffraction. In 1, pbc^? ligands link two Co(II) centers as μ₂-N,O and μ₂-N,O,O. Co(II) is six coordinate, octahedral. In 2, Co(II) is coordinated by four oxygens and two nitrogens. The ligands are μ₂-N,O,O and μ₃-N,O,O. Through different pbc^? ligands, 2 generates a 3-D network composed of six-connected nodes. Compound 2 exhibits good photoluminescence, whereas 1 is nonemissive at room temperature.     

Synthesis and reactivity of a novel hydridocobalt(III) complex containing trimethylphosphine and thiophenolato ligands

The novel hydridocobalt(III) complex [mer-Co(H)(SPh)₂(PMe₃)₃] (1) was prepared by reaction of thiophenol with [Co(PMe₃)₃Cl], [Co(PMe₃)₄] and [Co(PMe₃)₄Me]. A dinuclear cobalt dithiophenolato complex [Co(PMe₃)₂(SPh)]₂ (2) was obtained from the reaction of thiophenol with [Co(PMe₃)₄Me]. Reaction of 1 with iodomethane afforded complex [Co(PMe₃)₃(I)₂] (3). Reaction of complex 2 with carbon monoxide gave a mononuclear dicarbonyl cobalt(I) complex [Co(PMe₃)₃(CO)₂(SPh)] (4). The crystal structures of 1-4 were determined by X-ray diffraction. Formation mechanism of 1 is discussed.     

Die Kristallstruktur der hydratisierten Cyanokomplexe NMe4MnII[(Mn, Cr)III(CN)6] · 3 H2O und NMe4Cd[MIII(CN)6] · 3 H2O (MIII = Fe,Co): Verwandte des Berliner Blaus

The Crystal Structure of the Hydrated Cyano Complexes NMe₄Mn^II[(Mn, Cr)^III(CN)₆] · 3 H₂O and NMe₄Cd[M^III(CN)₆] · 3 H₂O (M^III = Fe, Co): Compounds Related to Prussian Blue The crystal structures of the isotypic tetragonal compounds (space group I4, Z = 10) NMe₄Mn^II · [(Mn, Cr)^III(CN)₆] · 3 H₂O (a = 1653.2(4), c = 1728.8(6) pm), NMe₄Cd[Fe(CN)₆] · 3 H₂O (a = 1642.7(1), c = 1733.1(1) pm) and NMe₄Cd[Co(CN)₆] · 3 H₂O (a = 1632.1(2), c = 1722.4(3) pm) were determined by X‐rays. They exhibit ⊥ c cyanobridged layers of octahedra [M^III(CN)₆] and [M^IIN₄(OH₂)₂], which punctually are interconnected also || c to yield altogether a spaceous framework. The M^II atoms at the positions linking into the third dimension are only five‐coordinated and form square pyramids [M^IIN₅] with angles N–M^II–N near 104° and distances of Mn–N: 1 × 214, 4 × 219 pm; Cd–N: 1 × 220 resp. 222, 4 × 226 resp. 228 pm. Further details and structural relations within the family of Prussian Blue are reported and discussed.     

Crystal and molecular structures of the Rh[(C2H5O)2PS2]3 and Co[(C6H5O)2PS2]3 chelate compounds

The crystal structures of the Rh[(EtO)₂PS₂]₃ (I) and Co[(PhO)₂PS₂]₃ (II) chelate compounds were determined from X-ray diffraction (XRD) data (CAD-4 diffractometer, MoK _β radiation, 1193 F _hkl , R = 0.0516 for I and 513 F _hkl , R = 0.0305 for II). Crystals I are monoclinic: a = 14.233(3) Å, b = 13.570(3) Å, c = 14.272(3) Å; β = 90.66(3)°, V = 2756.3(10) ų, Z = 4, ρ_calc = 1.587 g/cm³, space group C2/c. Crystals II are trigonal: a = 15.149(2) Å, c = 30.306(6) Å; V = 6023.2(16) ų, Z = 6, ρ_calc = 1.493 g/cm³, space group R3ˉ. Structures I and II consist of discrete mononuclear molecules. The coordination polyhedra of the M atoms (M = Rh, Co) are distorted octahedra formed by six sulfur atoms of three cyclic bidentate (RO)₂ PS₂⁻ ligands. Original Russian Text Copyright ? 2008 by R. F. Klevtsova, L. A. Glinskaya, and S. V. Larionov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 2, pp. 330–334, March–April, 2008.     

Structural and Physicochemical Characteristics of Tetrabutylammonium Tetrahalogenoferrates(III), [(C4H9)4N][FeBr4−nCln]

A series of tetrahalogenoferrates(III), [FeBr_4?nCl_n]^? (n=0‐4) stabilized with the tetrabutylammonium cation, of general formula [(C₄H₉)₄N][FeBr_4?nCl_n], has been synthesized. The crystal and molecular structure of [(C₄H₉)₄N][FeCl₄] was determined. The iron cation adopts slightly distorted tetrahedral coordination with two opposite angles smaller than tetrahedral one, two equal to tetrahedral and two larger than tetrahedral. The bond valences were computed. The total valence of iron atom is equal to 3.08. In the structure can be found only one hydrogen bond C(1)–H···Cl. Except mentioned there are no unusually intermolecular short contacts between ions existing in the structure. All [(C₄H₉)₄N][FeBr_4?nCl_n] (n=0‐4) compounds are isostructural in solid state. On the basis of conductometric measurements, relative stabilities of the anions have been estimated in methanol (MeOH), dimethyl sulfoxide (DMSO), acetone (AC), acetonitrile (AN) and dichloromethane (CH₂Cl₂) representing both polar (including amphiprotic and aprotic) as well as non‐polar solvents. Further, the dissociation constants of the compounds were calculated from the expanded Pitt's conductivity equation. The results of the conductometric measurements were supported by electronic spectra.     

Synthesis,characterizations and crystal structures of new antimony (III) complexes with dithiocarbamate ligands

Eight new antimony (III) complexes containing dithiocarbamate ligands (R₂NCS₂)₂SbBr [R₂NCS₂ = OC₄H₈NCS₂ (1), C₂H₅NC₄H₈NCS₂ (2), Me₂NCS₂ (3), C₄H₈NCS₂ (4)] and (R₂NCS₂)₃Sb[R₂NCS₂ = C₅H₁₀NCS₂ (5), Bz₂NCS₂ (6), Et₂NCS₂ (7), (HOCH₂CH₂)₂NCS₂ (8)] have been synthesized by the reactions of antimony (III) halides with dithiocarbamate ligands in 1:2 or 1:3 stoichiometries. All the complexes have been characterized by elemental analysis, melting point as well as spectral [IR and NMR (¹H and ¹³C)] studies. The crystal structures of complexes 1, 5 and 8 have been determined by X-ray single crystal diffraction, and their electrochemical character has also been studied.     

THE PHENOMENON OF CONGLOMERATE CRYSTALLIZATION. PART 54. THE CRYSTALLIZATION MODES OF FIVE NEW COMPLEXES [TRANS-(3,2,3-TET)Co(III)X 2]Y,X=NO− 2, CN−, NCS−

Abstract

A few complexes of formula [trans-Co(N₄)X ₂]Y, where X = a monodentate ligand, N₄ = a tetraamine ligand and Y = a halide or oxy anion have been found to crystallize as conglomerates; however, the majority crystallize as racemates. The complexes are of such variety of composition and packing characteristics that it is difficult to ascertain why they crystallize in one form or the other. We decided to investigate a series of [trans-Co(N₄)X ₂]Y compounds in which the amine was kept constant in order to limit the variables that affect the outcome.

Five different compounds of composition [trans-Co(3,2,3-tet)X ₂]Y (3,2,3-tet = 1,10-diamino-4,7-diaza-decane, X = NO^? ₂, CN^?, SCN^?, and Y = BF^? ₄, Cl^?, Br^?, I^?) were prepared and their crystallization behavior examined by determining their crystal structures. In all cases, when crystallized from deionized water at 21°C, these substances are racemates. Suggestions regarding this crystallization mode are offered in the discussion.     

Four-component relativistic calculations of NMR shielding constants of the transition metal complexes. Part 1: Pentaammines of cobalt,rhodium, and iridium

The nonrelativistic and four-component fully relativistic calculations of ¹H, ¹⁵N, ⁵⁹Co, ¹⁰³Rh, and ¹⁹³Ir shielding constants of pentaammineaquacomplexes of cobalt(III), rhodium(III), and iridium(III) were carried out at the density functional theory (DFT) level of theory. The noticeable deshielding relativistic corrections were observed for nitrogen shielding constants (chemical shifts), whereas those corrections were found to be negligible for protons. For the transition metals cobalt, rhodium, and iridium, relativistic corrections to their nuclear magnetic resonance (NMR) shielding constants were found to be rather small for cobalt and rhodium (some 5–10%), whereas they are essentially larger for iridium (up to 70%).     

Mesityl‐phenolato‐vanadium(III)‐Komplexe: Synthese,Struktur und Verhalten

Mesityl‐vanadium(III)‐phenolate Complexes: Synthesis, Structure, and Reactivity Protolysis reactions of [VMes₃(THF)] with ortho‐substituted phenols (2‐iso‐propyl‐(H–IPP), 2‐tert‐butyl(H–TBP), 2,4,6‐trimethylphenol (HOMes) and 2,2′biphenol (H₂–Biphen) yield the partially and fully phenolate substituted complexes [VMes(OAr)₂(THF)₂] (OAr = IPP ( 1 ), TBP ( 2 )), [VMes₂(OMes)(THF)] ( 4 ), [V(OAr)₃(THF)₂] (OAr = TBP ( 3 ), OMes ( 5 )), and [V₂(Biphen)₃(THF)₄] ( 6 ). Treatment of 6 with Li₂Biphen(Et₂O)₄ results in formation of [{Li(OEt₂)}₃V(Biphen)₃] ( 7 ) and with MesLi complexes [{Li(THF)₂}₂VMes(Biphen)₂] · THF ( 8 ) and [{Li(DME)}VMes₂(Biphen)] ( 9 ) are formed. Reacting [VCl₃(THF)₃] with LiOMes in 1 : 1 to 1 : 4 ratios yields the componds [VCl_3–n(OMes)_n(THF)₂] (n = 1 ( 5 b ), 2 ( 5 a ), 3 ( 5 )) and [{Li(DME)₂}V(OMes)₄] ( 5 c ), the latter showing thermochromism due to a complexation/decomplexation equilibrium of the solvated cation. The mixed ligand mesityl phenolate complexes [{Li(DME)_n}{VMes₂(OAr)₂}] (OAr = IPP ( 10 ), TBP ( 11 ), OMes ( 12 ) (n = 2 or 3) and [{Li(DME)₂}{VMes(OMes)₃}] ( 15 ) are obtained by reaction of 1 , 2 , 5 a and 5 with MesLi. With [{Li(DME)₂(THF)}{VMes₃(IPP)}] ( 13 ) a ligand exchange product of 10 was isolated. Addition of LiOMes to [VMes₃(THF)] forming [Li(THF)₄][VMes₃(OMes)] ( 14 ) completes the series of [Li(solv.)_x][VMes_4–n(OMes)_n] (n = 1 to 4) complexes which have been oxidised to their corresponding neutral [VMes_4–n(OMes)_n] derivatives 16 to 19 by reaction with p‐chloranile. They were investigated by epr spectroscopy. The molecular structures of 1 , 3 , 5 , 5 a , 5 a – Br , 7 , 10 and 13 have been determined by X‐ray analysis. In 1 (monoclinic, C2/c, a = 29.566(3) Å, b = 14.562(2) Å, c = 15.313(1) Å, β = 100.21(1)°, Z = 8), 3 (orthorhombic, Pbcn, a = 28.119(5) Å, b = 14.549(3) Å, c = 17.784(4) Å, β = 90.00°, Z = 8), ( 5 ) (triclinic, P1, a = 8.868(1) Å, b = 14.520(3) Å, c = 14.664(3) Å, α = 111.44(1)°, β = 96.33(1)°, γ = 102.86(1)°, Z = 2), 5 a (monoclinic, P2₁/c, a = 20.451(2) Å, b = 8.198(1) Å, c = 15.790(2) Å, β = 103.38(1)°, Z = 4) and 5 a – Br (monoclinic, P2₁/c, a = 21.264(3) Å, b = 8.242(4) Å, c = 15.950(2) Å, β = 109.14(1)°, Z = 4) the vanadium atoms are coordinated trigonal bipyramidal with the THF molecules in the axial positions. The central atom in 7 (trigonal, P3c1, a = 20.500(3) Å, b = 20.500(3) Å, c = 18.658(4) Å, Z = 6) has an octahedral environment. The three Li(OEt₂)⁺ fragments are bound bridging the biphenolate ligands. The structures of 10 (monoclinic, P2₁/c, a = 16.894(3) Å, b = 12.181(2) Å, c = 25.180(3) Å, β = 91.52(1)°, Z = 4) and 13 (orthorhombic, Pna2₁, a = 16.152(4) Å, b = 17.293(6) Å, c = 16.530(7) Å, Z = 4) are characterised by separated ions with tetrahedrally coordinated vanadate(III) anions and the lithium cations being the centres of octahedral and trigonal bipyramidal solvent environments, respectively.     

Disproportionation of rhenium(V). Imidazolate coordination of pyridylbenzimidazole in a rhenium(III) complex

Reaction of trans-[ReOCl₃(PPh₃)₂] with 2-(2′-pyridyl)benzimidazole (pbiH) in methanol led to the isolation of the rhenium(III) compound [ReCl₂(pbi)(PPh₃)₂] (1). Complex 1 could also be prepared in better yield by the reduction of [ReO₄]^? with PPh₃ in the presence of pbiH and hydrochloric acid. An X-ray crystallographic study showed that pbi is coordinated as a bidentate monoanionic chelate, with deprotonation of the imidazolyl NH group. The PPh₃ ligands are trans to each other.     

Solvothermal syntheses and structures of indium(III)-binaphthalenyl dicarboxylate complexes with yellow/blue luminescence

Two novel In(III) complexes, [In(bna)(Hbna)]_n (1) and [In₂(bna)₂(μ₂-OH)₂]_n·4nH₂O (2) (H₂bna=2,2′-dihydroxy-1,1′-binaphthyl-3,3′-dicarboxylate acid), have been reported. Complex 1 adopts a 2D layer structure, where each layer composed from homochiral ligands is chiral while the ligands in two neighboring layers are enantiomer. Complex 2 is constructed by individual -In-O-In- chains, which are further connected by bna²⁻ into a 3D honeycomb framework. As a derivative of H₂bna ligand, dmbna (3) was recrystallized for structurally comparison with 1-2 (dmbna=dimethyl 2,2′-dihydroxy-1,1′-binaphthyl-3,3′-dicarboxylate). X-ray powder diffractions (XRD) and thermogravimetric analyses (TGA) for 1-2 show that they are highly thermally stable in the solid state. Complexes 1 and 2 exhibit the intense yellow luminescence at 573 nm and blue luminescence at 459 nm at room temperature, respectively. And an astonishing blue shift of 105 nm is observed for complex 1 when it is measured at 10 K.     

Kristallstrukturen von Verbindungen A2[MnF3(SO4)] (A = Rb,NH4, Cs): Jahn‐Teller‐Ordnung in Mangan(III)‐fluoridsulfaten. I.

Jahn‐Teller Ordering in Manganese(III) Fluoride Sulphates. I. Crystal Structures of A₂[MnF₃(SO₄)] (A = Rb, NH4, Cs) The three isostructural fluorosulphatomanganates(III) A₂[MnF₃(SO₄)] (A = Rb, NH₄, Cs) crystallize in space group P2₁/c, Z = 4. Rb₂[MnF₃(SO₄)]: a = 7.271, b = 11.091, c = 8.776Å, β = 92.26°, R = 0.033; (NH₄)₂[MnF₃(SO₄)]: a = 7.299, b = 10.157, c = 8.813Å, β = 91.51°, R = 0.025; Cs₂[MnF₃(SO₄)]: a = 7.365, b = 11.611, c = 9.211, β = 92.30°, R = 0.029. In the chain anions [MnF₃(SO₄)]^2— manganese(III) is coordinated by two trans‐terminal and two trans‐bridging fluorine ligands, and by the O‐atoms of two briding sulphate ligands in trans position. The Jahn‐Teller effect induces a variety of antiferrodistortive ordering resulting in distorted [MnF₄O₂] octahedra with alternating elongation of F—Mn—F — and O—Mn—O — axes, respectively. Thus, only asymmetrical bridges are formed.     

Syntheses and characterization of a new nano-structured bismuth(III) bromide coordination polymer; new precursor for preparation of bismuth(III) bromide and bismuth(III) oxide nanostructures

Nanoparticles of a Bi(III) coordination polymer, {[Bi(μ-4,4′-bipy)Br₄] · (4,4′-Hbipy)} _n (1) (4,4′-bipy = 4,4′-bipyridine), were synthesized by a sonochemical method. The new nanoparticles were characterized by scanning electron microscopy, X-ray powder diffraction (XRD), IR spectroscopy, and elemental analyses. Compound 1 was structurally characterized by single-crystal X-ray diffraction. The thermal stabilities of 1 as bulk and at nanosize were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The Bi₂O₃ and BiBr₃ nanostructures were obtained by calcinations of nanostructure of 1 in air and argon.     

Variation in coordinative property of two different N<Subscript>2</Subscript>O<Subscript>2</Subscript> donor Schiff base ligands with nickel(II) and cobalt(III) ions: characterisation and single crystal structure elucidation

A nickel(II) and a cobalt(III) complex of two different potentially tetradentate Schiff bases with different binding modes have been synthesised. The nickel(II) complex [NiL¹] · CH₃OH (1) was formed, on reacting the metal salt with a perfectly symmetrical N₂O₂ tetradentate Schiff base ligand H ₂ L ¹ , which is the 1:2 condensation product of 1,3-diamino propane and 2-hydroxyacetophenone. The cobalt(III) complex [Co(HL²)₃] · (ClO₄)₃ · H₂O (2) was synthesised using an asymmetric N₂O₂ tetradentate Schiff base ligand HL ² on condensing N,N-dimethyl-1,3-diamino propane with o-vanillin in 1:1 mmol ratio. Although both Schiff bases are N₂O₂ functionalised, they showed variation in their coordinative property with nickel(II) and cobalt(III) ions. Both the complexes were characterised by IR spectroscopy and cyclic voltammetry and their single crystal structures clearly indicate that 1 is a mononuclear species whereas 2 is a hydrogen-bonded dimer.