The first salt of an isolated penta­chloro­plumbate(II) trianion

The title compound, tris(cyclo­hexane‐1,2‐diamine‐κ²N,N′)cobalt penta­chloro­plum­bate sesquihydrate, [Co(C₆H₁₄N₂)₃][PbCl₅]·1.5H₂O, crystallizes in the monoclinic space group C2/c, with a tricationic cobalt complex, a penta­chloro­plumbate trianion, one water mol­ecule in a general position and a second water mol­ecule on a crystallographic twofold axis. The compound is the first example of an isolated [PbCl₅]³⁻ moiety; the Pb atom is coordinated in a square‐pyramidal fashion, with four longer bonds to Cl atoms in the basal plane and a shorter distance to the apex. The ionic constituents and the solvent mol­ecules form a three‐dimensional network of hydrogen bonds.     

Tetraiodide von Tris(1,2‐ethandiamin)komplexen der Metalle Zink und Nickel

The isotypic compounds tris(1,2‐ethanedi­amine‐N,N′)­zinc(II) triiodide iodide, [Zn(C₂H₈N₂)₃](I₃)I, and tris(1,2‐ethanedi­amine‐N,N′)­nickel(II) triiodide iodide, [Ni(C₂H₈N₂)₃](I₃)I, contain the octahedral [M(en)₃]²⁺ cation, with M = Zn and Ni, in both enantiomeric forms, an essentially linear triiodide anion and an iodide anion. The geometries of the complex ions are as expected, e.g.d(Ni—N) = 2.123 (5), 2.127 (6) and 2.134 (5) Å, and d(Zn—N) = 2.176 (4), 2.193 (4) and 2.210 (4) Å. The shortest contact between the triiodide and iodide ions is 3.979 (1) Å for the nickel compound and 4.013 (1) Å for the zinc compound.     

Synthesis and Oxidative Stability of an Anionic Perfluoroethyl Cobalt(III) Complex

Upon reaction of the versatile tris(perfluoroethyl) cobalt(III) precursor [fac-(MeCN)₃Co(C₂F₅)₃] with potassium tris(pyrazolyl)borate (KTp) in the presence of a tetraphenylphosphonium salt, κ²- and κ³- adducts of the scorpionate ligand with cobalt were observed. Heating this mixture to 50 °C induced complete κ³-coordination of the Tp ligand to cobalt to afford the anionic complex [PPh₄][(κ³-Tp)Co(C₂F₅)₃] in 81 % yield. This new fluoroalkyl cobalt complex was characterized by NMR and UV-Vis spectroscopies, X-ray crystallography, and cyclic voltammetry. The oxidation of [PPh₄][(κ³-Tp)Co(C₂F₅)₃] occurs at much less-positive potentials relative to the related [(MeCN)₃Co(C₂F₅)₃] and [(tpy)Co(C₂F₅)₃] derivatives.     

A nitronyl nitro­xide complex of ­nickel(II) with nitrate as a ligand

The complex cation in [4,5-di­hydro-4,4,5,5-tetra­methyl-2-(2-pyridyl-κN)­imidazol-1-oxyl 3-oxide-κO³](nitrato-κ²O,O′)(N,N,N′,N′-tetra­methyl-1,2-ethanedi­am­ine-κ²N,N′)­nickel(II) hexafluorophosphate dichloromethane solvate, [Ni(NO₃)(C₆H₁₆N₂)(C₁₂H₁₆N₃O₂)]PF₆·CH₂Cl₂, is the first example of a nitro­nyl nitro­xide complex of a transition metal ion having d electrons in which nitrate is coordinated as a bidentate ligand. Owing to the smaller steric requirement of NO₃⁻, the Ni—­O(nitro­xide) bond length [2.014 (2) Å] is remarkably shorter than that in the corresponding ­β-­diketonate complexes [2.052 (4)–2.056 (2) Å].     

Two saccharinate complexes: [Mn(phen)2(sac)(H2O)]+·sac– and [Co(bipy)2(sac)(H2O)]+·sac–

The title saccharinate complexes, aqua[1,2‐benzisothiazol‐3(2H)‐onato 1,1‐dioxide‐N]bis(1,10‐phenanthroline‐N,N′)man­ganese(II) 1,2‐benz­isothia­zol‐3(2H)‐onate 1,1‐dioxide,[Mn(C₇H₄NO₃S)(C₁₂H₈N₂)₂(H₂O)](C₇H₄NO₃S), and aqua[1,2‐benz­iso­thiazol‐3(2H)‐onato 1,1‐dioxide‐N]­bis­(2,2′‐bi­pyri­dine‐N,N′)­cobalt(II) 1,2‐benz­iso­thia­zol‐3(2H)‐onate 1,1‐di­oxide, [Co­(C₇H₄NO₃S)­(C₁₀H₈N₂)₂­(H₂O)]­(C₇H₄NO₃S), have been prepared and their crystal structures determined at 150 K. The structure of the manganese complex consists of repeated alternating [Mn(phen)₂(sac)(H₂O)]⁺ cations and non‐coordinated saccharinate anions. The water molecule, bound to manganese as part of a slightly distorted octahedral arrangement, is hydrogen bonded to an O atom of the SO₂ group in the saccharinate counter‐ion. In contrast, the cobalt complex has one pseudo‐octahedral [Co(bipy)₂(sac)(H₂O)]⁺ cation, with the cobalt‐bound water molecule hydrogen bonded to the N atom of the accompanying free saccharinate anion.     

Two polymorphs of tris(ethylenediamine)cobalt(III) tetrathioantimonate(V)

Details of the structures of two polymorphs of tris(ethylenediamine)cobalt(III) tetrathioantimonate(V), [Co(C₂H₈N₂)₃][SbS₄], are reported. The first polymorph crystallizes in the orthorhombic space group Pna2₁, whereas the second polymorph belongs to the tetragonal space group P4₂bc. Both structures contain octahedral [Co(en)₃]³⁺ cations (en is ethylenediamine) and tetrahedral [SbS₄]³⁻ anions, which are interconnected via various N—H...S hydrogen bonds to form two different types of three‐dimensional network.     

The new thioantimonate(V) (C3H10N)[NiSbS4(C6H18N4)]

Turquoise crystals of the title salt, propyl­ammonium di‐μ‐thio‐1:2κ⁴S‐di­thio‐2κ²S‐tris(2‐amino­ethyl)­amine‐1κ⁴N‐anti­mony(V)­nickel(II), (C₃H₁₀N)[NiSbS₄(C₆H₁₈N₄)] or [PAH][Ni(tren)SbS₄] [where tren is tris(2‐amino­ethyl)­amine and PA is propyl­amine], were synthesized under solvothermal conditions by reacting [Ni(tren)₂]Cl₂, Sb and S in a solution of PA. The Ni^II ion is octahedrally surrounded by four N atoms of the tetradentate tren mol­ecule and by two S atoms of the tetrahedral [Sb^VS₄]^3? anion, thus forming the anionic [Ni(tren)SbS₄]^? part of the compound. Charge balance is achieved through the PAH⁺ cation. An extended intermolecular hydrogen‐bonding network is observed between the anion and the cation.     

Crystal structure of tris(ethylenediamine)cobalt(III) (aqua)hexachloromercurate(II) chloride [Co(En)3]2[Hg2(H2O)Cl6]Cl4

The compound [Co(En)₃]₂[Hg₂(H₂O)Cl₆]Cl₄ (I, En is ethylenediamine) has been synthesized and studied by X-ray diffraction. The crystals of I (a = 21.8745(14) Å, b = 10.6008(6) Å, c=15.4465(12) Å, space group Pna2₁) consist of tris(ethylenediamine)cobalt(III) complexes (the unit cell contains two [Co(En)₃]³⁺ cations of opposite chirality). [Hg₂(H₂O)Cl₆]^2? anions, and isolated chloride ions. The complex anion consists of the tetrahedral [HgCl₄]^2? group (Hg-Cl, 2.44–2.56 Å) and the hydrated molecule [Hg(H₂O)Cl₂] (Hg-Cl, 2.301 and 2.308 Å; Hg-O, 2.788 Å) combined by weak Hg-Cl interactions (2.915 and 3.220 Å).     

Bis­[tris­(ethyl­enedi­amine)­cobalt(III)] di­chloro­bis­[μ‐(1‐hydroxy­ethyl­idene)­di­phospho­nato(4–)]­di­ruthenium(II,­III)­(Ru–Ru) chloride trihydrate

In the title compound, [Co(C₂H₈N₂)₃]₂[Ru₂(C₂H₄O₇P₂)₂Cl₂]Cl·3H₂O, the building unit contains two crystallographically independent dinuclear [Ru₂(hedp)₂Cl₂]⁵⁻ anions, where hedp [viz. (1‐hydroxy­ethyl­idene)­di­phospho­nate] serves as a bis‐chelating bridging ligand, two types of [Co(en)₃]³⁺ cations, one uncoordinated Cl⁻ anion and five water mol­ecules of crystallization. The [Ru₂(hedp)₂Cl₂]⁵⁻ anions are connected to one another, forming one‐dimensional chains along the a axis. The [Co(en)₃]³⁺ cations are located between these chains and lie across inversion centres. An extensive series of hydrogen bonds lead to the formation of a three‐dimensional supramol­ecular network structure, with channels generated along the [100] direction. The uncoordinated water mol­ecules and Cl⁻ anions reside in these channels.     

Three-layered close packing in the crystal structure of tris(ethylenediamine)cobalt(III) hexanitrorhodate(III) hydrate, [Co(en)3][Rh(NO2)6]·3H2O,en=C2H8N2

In the structure of cubic tris(ethylenediamine)cobalt(III) hexanitrorhodate(III) hydrate, [Co(en)₃][Rh(NO₂)₆]·3H₂O, en=C₂H₈N₂, with a=16.540(5) Å, space group Pa3 (nonstandard, reduced to orthorhombic Pcab), the complex cations, anions, and water molecules are arranged by the law of three-layered (fcc) close packing of “quasispherical” species according to two structural types, NaCl and CaF₂. The packing is formed of [Rh(NO₂)₆]^3? anions, which also fill the octahedral voids. The tetrahedral voids are occupied by the central atoms of the [Co(en)₃]³⁺ cations, and the H₂O molecules lie between the cations, performing the packing function: the Ow...N_en contacts of 3.04 Å and the Ow..O_{NO 2} contacts of 3.01 Å characterize weak van der Waals interactions. The values of the interatomic distances Co?N, Rh?N, N?O, N?C, and C?C are in good agreement with the known data.     

Darstellung und Kristallstruktur von Tris(äthylendiamin)kobalt(III)-trichlorostannat(II)-dichlorid, [Co(en)3][SnCl3]Cl2

Preparation and Crystal Structure of Tris(ethylenediamine) cobalt(III)-trichlorostannate(II)-dichloride, [Co(en)₃] [SnCl₃]Cl₂ The title compound has been prepared from [Co(en)₃]Cl₃ and SnCl₂ · 2H₂O in aqueous HCl solution. It crystallizes in the orthorhombic space group Pbca, with a = 21.906(7), b = 10.607(3), c = 15.356(7) Å. The crystal structure has been determined from 1606 independent reflections by Patterson snd Fourier syntheses, and has been refined by least squares methods to R = 0.074. The [Co(en)₃]³⁺ ion is found to have the conformation of Λ(δδλ) resp. Δ(λλδ). The structure of the [SnCl₃]^? ion corresponds to a distorted tetrahedron, in which one site is occupied by the stereochemically active 5s electron pair. The following Sn? Cl distances have been found 2.493(7), 2.492(5), 2.479(7) Å, the distances of the two anionic Cl atoms from Sn are >4 Å.     

Formation of polymeric chain assemblies of transition metal complexes with a multidentate Schiff-base

The new multidentate Schiff-base (E)-6,6′-((1E,1′E)-(ethane-1,2-diylbis(azan-1-yl-1-ylidene))bis(methan-1-yl-ylidene))bis(4-methyl-2-((E)(pyridine-2-ylmethylimino)methyl)phenol) H₂L and its polymeric binuclear metal complexes with Cr(III), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) are reported. The reaction of 2,6-diformyl-4-methyl-phenol with ethylenediamine in mole ratios of 2:1 gave the precursor 3,3′-(1E,1′E)-(ethane-1,2-diylbis(azan-1-yl-1ylidene))bis(methan-1-yl-1-ylidene)bis(2-hydroxy-5-methylbenzaldehyde) W. Condensation of the precursor with 2-(amino-methyl)pyridine in mole ratios of 1:2 gave the new N₆O₂ multidentate Schiff-base ligand H₂L. Upon complex formation, the ligand behaves as a dibasic octadentate species with the involvement of the nitrogen atoms of the pyridine groups in coordination for all complexes. The mode of bonding and overall geometry of the complexes were determined through physico-chemical and spectroscopic methods. These studies revealed octahedral geometries for Cr(III), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Cd(II) and Hg(II) complexes of general formulae [Cr₂^III(L)Cl₂]Cl₂, [Ni₂^II(L)(H₂O)₂]Cl₂ and [M₂(L)Cl₂] and five co-ordinate Zn(II) complex of general formula [Zn₂^II(L)]Cl₂.     

Syntheses,characterization, and crystal structures of ruthenium(II)/(III) complexes with tridentate salicylaldiminato ligands

Treatment of [Ru(PPh₃)₃Cl₂] with one equivalent of tridentate Schiff base 2-[(2-dimethylamino-ethylimino)-methyl]-phenol (HL) in the presence of triethylamine afforded a ruthenium(III) complex [RuCl₃(κ²-N,N-NH₂CH₂CH₂NMe₂)(PPh₃)] as a result of decomposition of HL. Interaction of HL and one equivalent of [RuHCl(CO)(PPh₃)₃], [Ru(CO)₂Cl₂] or [Ru(tht)₄Cl₂] (tht = tetrahydrothiophene) under different conditions led to isolation of the corresponding ruthenium(II) complexes [RuCl(κ³-N,N,O-L)(CO)(PPh₃)] (2), [RuCl(κ³-N,N,O-L)(CO)₂] (3), and a ruthenium(III) complex [RuCl₂(κ³-N,N,O-L)(tht)] (4), respectively. Molecular structures of 1·CH₂Cl₂, 2·CH₂Cl₂, 3 and 4 have been determined by single-crystal X-ray diffraction.     

Syntheses,structures and magnetic properties of two CoII/NiII isostructural coordination polymers based on an asymmetric semirigid tricarboxylate ligand

Two new isostructural complexes, namely, poly[aqua[μ₃-2-(4-carboxyphenoxy)terephthalato-κ³O¹:O⁴:O^4′](1,10-phenanthroline-κ²N,N′)cobalt(II)], [Co(C₁₅H₈O₇)(C₁₂H₈N₂)(H₂O)]_n or [Co(μ₃-Hcpota)(phen)(H₂O)]_n, I , and poly[aqua[μ₃-2-(4-carboxyphenoxy)terephthalato-κ³O¹:O⁴:O^4′](1,10-phenanthroline-κ²N,N′)nickel(II)], [Ni(C₁₅H₈O₇)(C₁₂H₈N₂)(H₂O)]_n or [Ni(μ₃-Hcpota)(phen)(H₂O)]_n, II , have been synthesized by solvothermal reactions. Complexes I and II were fully characterized by IR spectroscopy, elemental analyses, thermogravimetric analyses, and powder and single-crystal X-ray diffraction. They both present two-dimensional structures based on [M₂(μ-COO)₂]²⁺ (M = Co^II or Ni^II) dinuclear metal units with a fes topology and a vertex symbol (4·8²). Interestingly, the positions of the two dimeric metal motifs and the two partially deprotonated Hcpota^2? ligands reproduce regular flying butterfly arrangements flipped upside down and sharing wings in the ab plane. Magnetic studies indicate antiferromagnetic interactions (J = ?5.21 cm^?1 for I and ?11.53 cm^?1 for II ) in the dimeric units, with Co…Co and Ni…Ni distances of 4.397 (1) and 4.358 (1) Å, respectively, that are related to double syn–anti carboxylate bridges.     

A saccharinate–iron(II) complex with a free saccharin molecule present, [Fe(phen)3]sac2·sacH·6H2O

The crystal structure of the title compound, tris(1,10-phenanthroline-N,N′)­iron(II) bis­[1,2-benziso­thia­zol-3(2H)-onate 1,1-dioxide] 1,2-benziso­thia­zol-3(2H)-one 1,1-dioxide hexahydrate, [Fe(C₁₂H₈N₂)₃](C₇H₄NO₃S)₂·C₇H₅NO₃S·6H₂O, at 120 K consists of slightly distorted octahedral [Fe(phen)₃]²⁺ cations (phen is 1,10-phenanthroline), two saccharinate anions and a free saccharin mol­ecule, as well as six waters of crystallization. The compound has been confirmed as diamagnetic low-spin iron(II) by magnetic measurements. There is extensive hydrogen bonding leading to a three-dimensional network.     

Synthesis and characterization of cobalt(III) tetraaza macrocyclic complexes containing chloro and azido ligands

The complexes [Co(L)Cl₂]Cl · 4H₂O (1) and [Co(L)(N₃)₂]N₃ · 2H₂O (2) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo [14,4,0^1.18,0^7.12]docosane) have been synthesized, and structurally characterized by X-ray crystallography, spectroscopy and cyclic voltammetry. The crystal structure of (1) is centrosymmetric and the cobalt(III) atom has an axially elongated octahedral geometry with four nitrogen atoms of the macrocycle and two chloride ligands. The cobalt(III) ion in (2) is coordinated to four nitrogen atoms from the macrocycle, and two azide ligands in an octahedral environment, which forms the 1D polymer through hydrogen bonding contacts involving the cation, azide anion and solvent water molecules. Electronic spectra of the complexes also exhibit a low-spin octahedral environment. Cyclic voltammetry of the complexes undergoes a one-electron wave corresponding to Co(III)/Co(II) processes. The electronic spectra and electrochemical behaviors of the complexes are significantly affected by the nature of the axial ligands.     

Two lanthanum(III) complexes containing η2‐pyrazolate and η2‐1,2,4‐triazolate ligands: intramolecular C—H...N/O interactions and coordination geometries

The lanthanum(III) complexes tris(3,5‐diphenylpyrazolato‐κ²N,N′)tris(tetrahydrofuran‐κO)lanthanum(III) tetrahydrofuran monosolvate, [La(C₁₅H₁₁N₂)₃(C₄H₈O)₃]·C₄H₈O, (I), and tris(3,5‐diphenyl‐1,2,4‐triazolato‐κ²N¹,N²)tris(tetrahydrofuran‐κO)lanthanum(III), [La(C₁₄H₁₀N₃)₃(C₄H₈O)₃], (II), both contain La^III atoms coordinated by three heterocyclic ligands and three tetrahydrofuran ligands, but their coordination geometries differ. Complex (I) has a mer‐distorted octahedral geometry, while complex (II) has a fac‐distorted configuration. The difference in the coordination geometries and the existence of asymmetric La—N bonding in the two complexes is associated with intramolecular C—H...N/O interactions between the ligands.     

Werner Complexes with ω‐Dimethylaminoalkyl Substituted Ethylenediamine Ligands: Bifunctional Hydrogen‐Bond‐Donor Catalysts for Highly Enantioselective Michael Additions

The racemic carbonate complex [Co(en)₂O₂CO]⁺ Cl^? (en=1,2‐ethylenediamine) and (S)‐[H₃NCH((CH₂)_nNHMe₂)CH₂NH₃]³⁺ 3 Cl^? (n=1–4) react (water, charcoal, 100 °C) to give [Co(en)₂((S)‐H₂NCH((CH₂)_nNHMe₂)CH₂NH₂)]⁴⁺ 4 Cl^? ( 3 a – d H⁴⁺ 4 Cl^?) as a mixture of Λ/Δ diastereomers that separate on chiral‐phase Sephadex columns. These are treated with NaOH/Na⁺ BAr_f^? (BAr_f=B(3,5‐C₆H₃(CF₃)₂)₄) to give lipophilic Λ‐ and Δ‐ 3 a–d ³⁺ 3 BAr_f^?, which are screened as catalysts (10 mol %) for additions of dialkyl malonates to nitroalkenes. Optimal results are obtained with Λ‐ 3 c ³⁺ 3 BAr_f^? (CH₂Cl₂, ?35 °C; 98–82 % yields and 99–93 % ee for six β‐arylnitroethenes). The monofunctional catalysts Λ‐ and Δ‐[Co(en)₃]³⁺ 3 BAr_f^? give enantioselectivities of <10 % ee with equal loadings of Et₃N. The crystal structure of Δ‐ 3 a H⁴⁺ 4 Cl^? provides a starting point for speculation regarding transition‐state assemblies.     

Synthesis and molecular structure of Cr(salen)(μ‐N)RhCl(COD): the first example of a heterobimetallic nitride‐bridged complex containing chromium

Five‐coordinate Cr(N)(salen) {salen is 2,2′‐[ethane‐1,2‐diylbis(nitrilomethylidyne)]diphenolate} reacts with [RhCl(COD)]₂ (COD is 1,5‐cyclooctadiene) to yield the heterobimetallic nitride‐bridged title compound, namely chlorido‐2κCl‐[2(η⁴)‐1,5‐cyclooctadiene]{2,2′‐[ethane‐1,2‐diylbis(nitrilomethylidyne)]diphenolato‐1κ⁴O,N,N′,O′}‐μ‐nitrido‐1:2κ²N:N‐chromium(V)rhodium(I), [CrRh(C₁₆H₁₄N₂O₂)ClN(C₈H₁₂)]. The Cr—N bond of 1.5936 (14) Å is elongated by only 0.035 Å compared to the terminal Cr—N bond in the precursor. The nitride bridge is close to being linear [173.03 (9)°] and the Rh—N bond of 1.9594 (14) Å is very short for a monodentate nitrogen‐donor ligand, indicating significant π‐acceptor character of the Cr[triple‐bond]N group.     

Tetrameric indium trichloride,a new modification of a widely used compound

The title compound, hexa‐μ‐chloro‐1:2κ⁴Cl;2:3κ⁴Cl;3:4κ⁴Cl‐hexachloro‐1κ²Cl,2κCl,3κCl,4κ²Cl‐hexakis­(diethyl­amine)‐1κ²N,2κN,3κN,4κ²N‐tetraindium(III), [(InCl₃)₄(Et₂NH)₆] or [In₄Cl₁₂(C₄H₁₁N)₆], lies about an inversion centre and consists of four octahedrally coordinated In centres linked by bridging Cl atoms to form three four‐membered In₂Cl₂ rings.