Die Kristallstruktur von Bis(N,N-diethyl-N′ -benzoylselenoureato)nickel(II)

The Crystal Structure of Bis(N,N-diethyl-N′ -benzoylselenoureato)nickel(II) Ni(C₁₂H₁₅N₂OSe)₂ crystallizes in the monoclinic space group P2₁/c. The cell parameters are a = 11.399(3), b = 16.016(4), c = 14.910(6) Å, β = 104.64(3)° and Z = 4. The structure was solved with Patterson and direct methods and was refined to a final R-value of 5.43%. Nickel is coordinated to two N,N-diethyl-N′ -benzoylselenourea molecules to form a bidentally coordinated chelate complex with cis arrangement of the donor atoms. Coordinaton around the nickel atom is planar while the chelate rings diverge from planarity. The ethyl groups of one diethylamino group are disordered. The Ni? Se bond lengths are 2.244(1) and 2.264(1) Å, the Ni? O bond lengths are 1.871(4) and 1.883(4) Å, respectively.     

2,6‐Bis[bis(2‐pyridiniomethyl)aminomethyl]‐4‐tert‐butylphenol dichloride diperchlorate hydrate

The title compound, C₃₆H₄₄N₆O⁴⁺·2Cl^?·2ClO₄^?·0.132H₂O, is shown to be protonated at all the pyridine N atoms; the two chloride ions are hydrogen bonded to three pyridine N atoms and to the phenolic O atom of the same cation [Cl?N = 3.045 (2)–3.131 (2) Å and Cl?O = 2.938 (2) Å], and the remaining pyridine N atom is hydrogen bonded to the phenolic O atom [N?O = 2.861 (2) Å]. The mean value of the C—N—C angle of the protonated pyridine rings is 123.4 (1)°, which is significantly larger than that found for unprotonated pyridine rings.     

Synthesis and Crystal Structure of the Tris‐bidentate Carbonatobis‐(1,10‐phenanthroline‐N,N′)nickel(II), [Ni(C12H8N2)2(CO3)]

The tris‐bidentate complex [Ni(C₁₂H₈N₂)₂(CO₃)] was synthesized by the reaction of Na₂CO₃, 1,10‐phenanthroline (phen = C₁₂H₈N₂) and NiSO₄ · 6 H₂O in the presence of succinic acid in a CH₃OH–H₂O solution. The compound crystallizes as heptahydrate. The crystal structure (monoclinic, P2₁/c (no. 14), a = 9.897(1), b = 26.384(2), c = 10.582(1) Å, β = 105.87(1)°, Z = 4, R = 0.0505, wR² = 0.1029 for 3166 observed reflections (F ≥ 2σ(F ) out of 6100 unique reflections) consists of hydrogen bonded water molecules and [Ni(phen)₂(CO₃)] complex molecules. The Ni atoms are sixfold octahedrally coordinated by the four N atoms of two bidentate chelating phen ligands and by two O atoms of the bidentate chelating carbonate group with d(Ni–N) = 2.092–2.100 Å, d(Ni–O) = 2.051, 2.079 Å. The complex molecules are stacked into 2D corrugated layers parallel to (010) via two types of intermolecular π‐π stacking interactions. One occurs between two quinoline rings of neighboring phen ligands at the distance of 3.63 Å in [010] direction and the other results from 1D π‐π stacking interactions through partially covered phen rings at alternative distances of 3.26 Å and 3.33 Å in [001] direction. The water molecules are sandwiched between 2D layers.     

Self‐Assembly,Spectroscopic and Electrochemical Studies of Nickel(II)‐4,8‐Diazaundecanediamide Complex

The self‐assembly of NiCl₂·6H₂O with a diaminodiamide ligand 4,8‐diazaundecanediamide (L‐2,3,2) gave a [Ni(C₉H₂₀N₄O₂)(Cl)(H₂O)] Cl·2H₂O ( 1 ). The structure of 1 was characterized by single‐crystal X‐ray diffraction analysis. Structural data for 1 indicate that the Ni(II) is coordinated to two tertiary N atoms, two O atoms, one water and one chloride in a distorted octahedral geometry. Crystal data for 1: orthorhombic, space group P 21nb, a = 9.5796(3) Å, b = 12.3463(4) Å, c = 14.6305(5) Å, Z = 4. Through NH···Cl–Ni (H···Cl 2.42 Å, N···Cl 3.24 Å, NH···Cl 158°) and OH···Cl–Ni contacts (H···Cl 2.36 Å, O···Cl 3.08 Å, OH···Cl 143°), each cationic moiety [Ni(C₉H₂₀N₄O₂) (Cl)(H₂O)]⁺ in 1 is linked to neighboring ones, producing a charged hydrogen‐bonded 1D chainlike structure. Thermogrametric analysis of compound 1 is consistent with the crystallographic observations. The electronic absorption spectrum of Ni(L‐2,3,2)²⁺ in aqueous solution shows four absorption bands, which are assigned to the ³A_2g → ³T_2g, ³T_2g → ¹Eg, ³T_2g → ³T_1g, and ³A_2g → ³T_1g transitions of triplet‐ground state, distorted octahedral nickel(II) complex. The cyclic volammetric measurement shows that Ni²⁺ is more easily reduced than Ni(L‐2,3,2)²⁺ in aqueous solution.     

Die Kristallstrukturen von [Cu2Cl2(AA · H+)2](NO3)2 und [AA · H+]Pikr− (AA · H+ = Allylammonium; Pikr− = Pikrat)

The Crystal Structures of [Cu₂Cl₂(AA · H⁺)₂](NO₃)₂ and [AA · H⁺]Picr^? (AA · H⁺ = Allylammonium; Picr^? = Picrat) By an alternating current electro synthesis the crystal-line π-complex [Cu₂Cl₂(AA · H⁺)₂](NO₃)₂ has been obtained from CuCl₂ · 2H₂O, allylamine (AA), and HNO₃ in ethanolic solution. X-ray structure analysis revealed that the compound crystallized in the monoclinic system, space group P2₁/a, a = 7.229(3), b = 7.824(3), c = 26.098(6) Å, γ = 94.46(5)°, Z = 4, R = 0.025 for 2 023 reflections. The crystal structure is built up of Cu_nCl_n chains which are connected by π-bonding bidentate AA · H⁺ …? ON(O)O …? H⁺ · AA units. For comparision with the above complex the structure of [AA · H⁺]Picr^? (Picr^? = picrate anion) is also reported.     

Homo- und heterodinukleare α-Pyridonat-verbrückte Platin- und Palladium-komplexe mit Bis(N-methylimidazol-2-yl)keton (BMIK). Kristallstrukturen von [(BMIK)Pt(α-Pyridonat)2Pt(BMIK)](NO3)2 · 4H2O, [(BMIK)Pd(α-Pyridonat)2Pd(BMIK)](NO3)2 · 4H2O und [(BMIK)Pd(α-Pyridonat)2Pt/Pd(BMIK)](NO3)2 · 4H2O

Homo- and Heterodinuclear α-Pyridonate-bridged Platinum and Palladium Complexes with Bis(N-methylimidazol-2-yl)ketone (BMIK). Crystal Structures of [(BMIK)Pt(α-pyridonate)₂Pt(BMIK)](NO₃)₂ · 4H₂O, [(BMIK)Pd(α-pyridonate)₂Pd(BMIK)](NO₃)₂ · 4H₂O, and [(BMIK)Pd(α-pyridonate)₂Pt/Pd(BMIK)](NO₃)₂ · 4H₂O The isotypic dinuclear complexes [(BMIK)Pt(α-pyridonate)₂Pt(BMIK)](NO₃)₂ · 4H₂O ( 1 ) (P1 ; a = 12.197(5) Å, b = 12.505(5) Å, c = 12.866(5) Å, α = 88.17(3)°, β = 73.55(3)°, γ = 69.84(3)°; Z = 2) and [(BMIK)Pd(α-pyridonate)₂Pd(BMIK)](NO₃)₂ · 4H₂O ( 2 ) (a = 12.408(3) Å, b = 12.660(3) Å, c = 12.913(3) Å, α = 89.55(3)°, β = 74.59(2)°, γ = 68.68(2)°) were prepared by reaction of [Pt(BMIK)(H₂O)₂](NO₃)₂ or [Pd(BMIK)(H₂O)₂](NO₃)₂ with α-pyridone in aqueous solutions at 40°C and were isolated as red air-stable crystals (BMIK = bis(N-methylimidazol-2-yl)ketone). For the synthesis of mixed crystals of 2 with the heterometal complex [(BMIK)Pd(α-pyridonate)₂Pt(BMIK)](NO₃)₂ · 4H₂O ( 3 ) (a = 12.430(4) Å, b = 12.648(3) Å, c = 12.907(4) Å, α = 89.64(2)°, β = 74.57(2)°, γ = 68.65(2)°) α-pyridone was reacted with [Pd(BMIK)(H₂O)₂](NO₃)₂ in a molar ratio of 2 : 1 followed by addition of [Pt(BMIK)(H₂O)₂](NO₃)₂. The dinuclear cations consist of two M(BMIK) moieties (M = Pt, Pd) bridged by the N- and O-atoms of α-pyridonate, forcing the heterocyclic ring into head-head-orientation. Within the dinuclear cation, the two metal atoms are between 2.840 Å and 2.860 Å apart. The intermolecular distances are between 4.762 Å and 4.837 Å. The coordination geometry of both metal atoms is square-planar with the metal atoms being diplaced slightly from their respective coordination planes toward each other. ¹H and ¹⁹⁵Pt NMR spectra are reported for the complexes.     

Synthese und Charakterisierung von Aquapentachloroplatinaten(IV) – Struktur von [K(18-Krone-6)][PtCl5(H2O)]

Synthesis and Characterization of Aquapentachloroplatinates(IV) – Structure of [K(18-crown-6)][PtCl₅(H₂O)] The crown ether complex of the aquapentachloroplatinic acid of the composition [H₁₃O₆][PtCl₅(H₄O₂)] · 2(18-cr-6) ( 2 ) reacts with K₂CO₃ and [NⁿBu₄]OH in aqueous solution to give [K(18-cr-6)][PtCl₅(H₂O)] ( 5 a ) and [NⁿBu₄][PtCl₅(H₂O)] · ¹/₂ (18-cr-6) · H₂O ( 5 b ), respectively. Both compounds were characterized by microanalysis, vibrational (IR, Raman) and NMR (¹H, ¹³C, ¹⁹⁵Pt) spectroscopy. The X-ray structure analysis of 5 a (orthorhombic, pnma; a = 16,550(4), b = 18,044(3), c = 7,415(1) Å; Z = 4; R1 = 0,0183; wR2 = 0,0414) reveals that the crystal is threaded by chains built up of [PtCl₅(H₂O)]^? and [K(18-cr-6)]⁺ units. There are tight K …? Cl contacts (d(K? Cl1)) = 3,0881(9) Å and O_W? H? O_cr hydrogen bridges (d(O1 …? O2) = 2,806(3) Å) between these units. The coordination polyhedron [PtCl₅O] has approximately C_4v symmetry.     

Nonanatrium-bis(hexahydroxoaluminat)-trihydroxid-hexahydrat (Na9[Al(OH)6]2(OH)3 · 6H2O) – Kristallstruktur,NMR-Spektroskopie und thermisches Verhalten

Nonasodium Bis(hexahydroxoaluminate) Trihydroxide Hexahydrate (Na₉[Al(OH)₆]₂(OH)₃ · 6H₂O) – Crystal Structure, NMR Spectroscopy and Thermal Behaviour The crystal structure of the nonasodium bis(hexahydroxoaluminate) trihydroxide hexahydrate Na₉[Al(OH)₆]₂(OH)₃ · 6H₂O (4.5 Na₂O Al₂O₃ · 13.5 H₂O) (up to now described as 3 Na₂O · Al₂O₃ · 6H₂O, 4Na₂O · Al₂O₃ · 13 H₂O and [3 Na₂O · Al₂O₃ · 6H₂O] [xNaOH · yH₂O], respectively) was solved. The X-ray single crystal diffraction analysis (triclinic, space group P1 , a = 8.694(1) Å, b = 11.344(2) Å, c = 11.636(3) Å, α = 74.29(2)°, β = 87.43(2)°, γ = 70.66(2)°, Z = 2) results in a structure, consisting of monomeric [Al(OH)₆]^3? aluminate anions, which are connected by NaO₆ octahedra groups. Furthermore the structure contains both, two hydroxide anions only surrounded by water of crystallization and OH groups of [Al(OH)₆]^3? aluminate anions and a hydroxide anion involved in three NaO₆ coordination octahedra directly and moreover connected with a water molecule by hydrogen bonding. The results of ²⁷Al and ²³Na-MAS-NMR investigations, the thermal behaviour of the compound and possible relations between the crystal structure and the conditions of coordination in the corresponding sodium aluminate solution are discussed as well.     

Copper(II)-assisted thorough hydrolysis of 2,4,6-tris(2-pyridyl)1,3,5-triazine (tptz). Crystal structures of bis(2-pyridylcarboxylato)-copper(II) dihydrate and bis(2-pyridylcarbonyl)-amido-2,4,6-tris(2-pyridyl)-1,3,5-triazine-copper(II) dicyanamide heptahydrate

2,4,6-Tris(2-pyridyl)-1,3,5-triazine (tptz) undergoes hydrolysis in the presence of copper(II) acetate affording bis(2-pyridylcarbonyl)amido-copper(II) and free 2-pyridylcarboxylic anion. Two compounds of formulas [Cu(NC₅H₄COO)₂]·2H₂O (1) and [Cu(NC₅H₄CO)₂N(tptz)](N(CN)₂)·7H₂O (2), where NC₅H₄COO^? and (NC₅H₄CO)₂N^? are 2-pyridylcarboxylate and bis(2-pyridylcarbonyl)amido-anion, respectively, were obtained from methanol/ethanol solution of tptz with copper acetate; they were characterized by element analysis and single crystal X-ray diffraction method. Single crystal XRD analysis shows that in complex 1 coordination number around Cu atom is 4 with distorted square-planar coordination geometry and in complex 2 coordination number around Cu atom is 6 with distorted octahedral geometry. Crystal data for 1: a = 5.1359(10) Å, b = 7.6471(15) Å, c = 9.2303(18) Å, α = 74.90(3)°, β = 84.36(3)°, γ = 71.37(3)°, space group P1, crystal system triclinic, Z = 1, V = 331.6(1) ų, d _calc = 1.721 g/cm³. Crystallographic data for 2: space group C2/c, crystal system monoclinic, a = 23.976(5) Å, b = 15.465(3) Å, c = 18.649(4) Å, β = 92.66(3)°, V = 6907(2) ų, d _calc = 1.0448 g/cm³, Z = 4.     

Structure of Perchlorato(2,5,8,11-Tetraazadodecane)Copper (II) Perchlorate Monohydrate

[Cu(C₈H₂₂N₄)]·(ClO₄)₂.H₂O, M_r= 454.80, orthorhombic C222₁, a = 15.481(5), b = 7.404(1), c = 14.827(3)Å, V = 1699.5(8)ų, Z = 4, D_x = 1.78 g/cm³, λ(MoKα) = 0.71073Å, μ = 16.5 cm^?1. F(000) = 940, T = 22°C, R = 6.86%, R_w = 7.66% for 820 observed reflections (I > 2.5σ (I)). The coordination number for the copper(II) ion is five, and the coordination geometry about copper(II) ion is a buckled square pyramid with the tetraamine equatorial and a perchlorate ion axial. The tetraamine is coordinated in a square-plannar manner with slight tetrahedral distortions. The four Cu-N distances span a very narrow range, 1.990(10) ?1.994(14)Å.     

Röntgenographische und spektroskopische Untersuchungen an Ba2Ni(N3)6· 3H2O

Preparation and X-Ray Examination of Ba₂Ni(N₃)₆ · 3 H₂O Ba₂Ni(N₃)₆ · 3 H₂O has been prepared by the reaction of an aqueous solution of Ba(N₃)₂ with basic nickel azide. The crystals are green, the lattice constants are: a = 7.09 Å, b = 7.09 Å, c = 16.30 Å, α = 74.58°, β = 105.42°, γ = 97.10°, N = 2. Optical spectra point to an octahedral microsymmetry of the azide ions around nickel.     

Syntheses and Structures of Two New Cu/Nb/pyrazine Complexes: Three dimensional CuNb(pyz)2OF5 · (pyz)(H2O) and two dimensional [Cu(pyz)2.5]+ [NbF6]− · (pyz)

Crystals of CuNb(pyz)₂OF₅ · (pyz)(H₂O) ( 1 ) and [Cu(pyz)_2.5]⁺ [NbF₆]^? · (pyz) ( 2 ) were grown (150°C and autogeneous pressures) from CuO, 1/2(Nb₂O₅), (HF)_x · pyridine, and H₂O in excess pyrazine. Light blue single crystals of ( 1 ) are orthorhombic, crystallizing in space group Cccm (No. 66), with a = 14.547(1) Å, b = 16.135(2) Å, c = 13.803(2) Å, and Z = 8. The structure of ( 1 ) contains corner shared [Cu(pyz)_4/2F_2/2]⁺, [Cu(pyz)_4/2O_2/2], and [NbF₄O_1/2F_1/2]^?0.5 octahedra. Orange crystals of ( 2 ) are monoclinic, crystallizing in space group C2/c (No. 15), with a = 11.792(8) Å, b = 17.123(3) Å, c = 17.051(5) Å, β = 90.04(4)°, and Z = 8. The structure of ( 2 ) contains puckered rings of corner shared [Cu(pyz)(pyz)_3/2]⁺ tetrahedra and isolated [NbF₆]^? anions within the rings.     

Aqua(dipicolinato‐κ3O2,N,O6)(1,10‐phenanthroline‐κ2N,N′)manganese(II) monohydrate

In the title compound [systematic name: aqua(1,10‐phenanthroline‐κ²N,N′)(pyridine‐2,6‐di­carboxyl­ato‐κ³O²,N,O⁶)manganese(II) monohydrate, [Mn(C₇H₃NO₄)(C₁₂H₈N₂)(H₂O)]·H₂O, the manganese(II) centre is surrounded by one bidentate phenanthroline ligand [Mn—N = 2.248 (3) and 2.278 (3) Å], one tridentate dipicolinate ligand [Mn—N = 2.179 (3) Å, and Mn—O = 2.237 (2) and 2.266 (2) Å] and one water mol­ecule [Mn—O = 2.117 (3) Å], and it exhibits a strongly distorted octahedral geometry, with trans angles ranging from 144.12 (9) to 158.88 (11)°. Extensive intermolecular hydrogen‐bonding interactions involving coordinated and uncoordinated water mol­ecules and the carboxyl O atoms of the dipicolinate ligand, as well as a stacking interaction involving the phenanthroline rings, are observed in the crystal structure.     

Synthesis and crystal structure of hydrated cation-anion nickel(II) thiosemicarbazide and nickel(II) malonate dihydrate complex

A crystal of Ni(HL)₂[Ni(Malon)₂(H₂O)₂]₂ · 3.51H₂O (I), which is built of [Ni(HL)₂]₂₊ cations (HL is thiosemicarbazide), [Ni(Malon)₂(H₂O)₂]_2? anions (H₂ Malon is malonic acid), and molecules of crystal water, has been synthesized and studied by IR spectroscopy, thermogravimetry, and X-ray diffraction. Structural units of complex I are linked by electrostatic interactions and numerous hydrogen bonds. The unit cell parameters b = 7.233(1) Å, c = 24.426(5) Å, β = 127.98(3)°, space group C2/c, Z = 8. The polyhedron of the nickel atom in [Ni(HL)₂]₂₊ cations is a cis-square that is slightly distorted within ～10°. Ligands HL are bidentately chelately coordinated (via N and S) to the nickel atom with the closure of near planar five-membered chelate rings. The malonate groups in [Ni(Malon)₂(H₂O)₂]^2? anions are bidentately chelately coordinated with the formation of six-membered non-planar chelate rings. The coordination of the central atom is complemented to an octahedron with two H₂O molecules. The bond lengths in cations are 1.924(4) and 1.912(4) Å (Ni-N) and 2.144(1) and 2.150(2) Å (Ni-S), and the bond lengths in anions are 2.003–2.046(3) Å (Ni-O) and 2.113(4) and 2.122(3) Å (Ni-O(w)).     

N,N′‐Di­methyl­piperazinium(2+) phos­phonoacetate: hydrogen‐bonded anion sheets containing cation‐templated R66(28) rings

In the title compound, C₆H₁₆N₂²⁺·2C₂H₄O₅P^?, the cations lie across centres of inversion; in the anions, two of the H‐atom sites have 0.50 occupancy. The anions are linked by short O—H?O hydrogen bonds [O?O 2.465 (3)–2.612 (3) Å and O—H?O 165–171°] into sheets of alternating R(12) and R(28) rings, both of which are centrosymmetric; the cations lie at the centres of the larger rings linked to the anion sheet by N—H?O hydrogen bonds [N?O 2.642 (2) Å and N—H?O 176°].     

A cobalt(III) compound of a 13‐membered cyclic tetra­amine: trans‐(12,12‐dimethyl‐1,4,7,10‐tetra­aza­cyclo­tetra­decane)diisothio­cyanato­cobalt(III) tetra­isothio­cyanato­zinc(II) ethanol solvate

The title compound, [Co(NCS)₂(C₁₁H₂₆N₄)]₂[Zn(NCS)₄]·C₂H₅OH, has two similar cations with the Co^III atom coordinated in a planar fashion by the 13‐membered cyclic tetra­amine, in the 1R,4S,7R,10S configuration, and with trans isothio­cyanate ligands. The six‐membered chelate ring is in a chair conformation, with one axially and one equatorially oriented methyl substituent [mean Co—N = 1.948 (2) Å]. The `opposite' chelate ring (N<sup>4</sup> and N<sup>7</sup>) is in an eclipsed conformation [mean Co—N = 1.928 (2) Å], and the `side' chelate rings have gauche conformations. The mean Co—N_NCS distance is 1.928 (2) Å. Both cations have one Co—N—C group nearly linear and the other appreciably bent, with mean Co—N—C angles of 178.7 (1) and 160.4 (1)°, respectively. The [Zn(NCS)₄]²⁻ anion is approximately tetra­hedral, with Zn—N = 1.951 (1)–1.986 (1) Å, N—Zn—N = 104.5 (1)–111.9 (1)° and Zn—N—C = 152.5 (1)–179.4 (1)°. One NH group is hydrogen bonded to the ethanol O atom and the other NH groups are bonded to thio­cyanate S atoms, forming a network.     

Crystal Structures of [Mn2(H2O)4(phen)2(C4H4O4)2] · 2 H2O and [Mn(phen)2(H2O)2][Mn(phen)2(C4H4O4)](C4H4O4) · 7 H2O

Reactions of 1,10‐phenanthroline monohydrate, Na₂C₄H₄O₄ · 6 H₂O and MnSO₄ · H₂O in CH₃OH/H₂O yielded a mixture of [Mn₂(H₂O)₄(phen)₂(C₄H₄O₄)₂] · 2 H₂O ( 1 ) and [Mn(phen)₂(H₂O)₂][Mn(phen)₂(C₄H₄O₄)](C₄H₄O₄) · 7 H₂O ( 2 ). The crystal structure of 1 (P1 (no. 2), a = 8.257(1) Å, b = 8.395(1) Å, c = 12.879(2) Å, α = 95.33(1)°, β = 104.56(1)°, γ = 106.76(1)°, V = 814.1(2) ų, Z = 1) consists of the dinuclear [Mn₂(H₂O)₄(phen)₂(C₄H₄O₄)₂] molecules and hydrogen bonded H₂O molecules. The centrosymmetric dinuclear molecules, in which the Mn atoms are octahedrally coordinated by two N atoms of one phen ligand and four O atoms from two H₂O molecules and two bis‐monodentate succinato ligands, are assembled via π‐π stacking interactions into 2 D supramolecular layers parallel to (101) (d(Mn–O) = 2.123–2.265 Å, d(Mn–N) = 2.307 Å). The crystal structure of 2 (P1 (no. 2), a = 14.289(2) Å, b = 15.182(2) Å, c = 15.913(2) Å, α = 67.108(7)°, β = 87.27(1)°, γ = 68.216(8)°, V = 2934.2(7) ų, Z = 2) is composed of the [Mn(phen)₂(H₂O)₂]²⁺ cations, [Mn(phen)₂(C₄H₄O₄)] complex molecules, (C₄H₄O₄)^2– anions, and H₂O molecules. The (C₄H₄O₄)^2– anions and H₂O molecules form 3 D hydrogen bonded network and the cations and complex molecules in the tunnels along [001] and [011], respectively, are assembled via the π‐π stacking interactions into 1 D supramolecular chains. The Mn atoms are octahedrally coordinated by four N atoms of two bidentate chelating phen ligands and two water O atoms or two carboxyl O atoms (d(Mn–O) = 2.088–2.129 Å, d(Mn–N) = 2.277–2.355 Å). Interestingly, the succinato ligands in the complex molecules assume gauche conformation bidentately to chelate the Mn atoms into seven‐membered rings.     

Crystal structures of copper(II) complexes with methyliminodiacetate ions and 1,10-phenanthroline or imidazole [Cu(Phen)H<Subscript>2</Subscript>O][Cu(Mida)<Subscript>2</Subscript>]·2H<Subscript>2</Subscript>O and [Cu(Mida)Im]

Methyliminodiacetic acid (H₂Mida) and imidazole react with copper(II) to form crystals of the square pyramidal complex [Cu(Mida)Im]. One N and two O atoms of the Mida ligand (Cu-N 2.010(1) Å, Cu-O 1.955(1) Å, and 1.978(1) Å) and the imidazole N atom (1.950(1) Å) lie at the base of the pyramid. The carboxyl O atom of the neighboring complex lies at the apical position (2.411(1) Å); in this way the individual complexes are linked into infinite zigzag chains. Substitution of imidazole by 1,10-phenanthroline gave [Cu₂(Mida)₂(Phen)H₂O]·2H₂O crystals with two nonequivalent centrosymmetric octahedral anions [Cu(Mida)₂]^2? of face type (Cu-N 2.023 Å and 2.028(2) Å, Cu-O_ax 2.579 Å and 2.530(2) Å, Cu-O_bas 1.952 Å and 1.936(2) Å). The anions serve as bridges in chains between the [Cu(Phen)H₂O]²⁺ cation fragments to which they are bonded by their axial carboxyl groups. The Cu atom of the cation has a [4+1] environment (with the H₂O molecule lying on the axis of the pyramid, and with two N atoms of the ligand and two O atoms of the anions lying at the base).     

Synthesis,Characterization and Crystal Structure of a Nickel(II) Schiff Base Complex Derived from Acetylacetone and Ethylenediamine

The square-planar nickel (II) complex of composition [Ni(bae)]·½H₂O (1) [where H₂bae is bis(acetylacetone)ethylenediamine] has been synthesized by [2 + 1] template condensation of acetylacetone and ethylenediamine in the presence of NiCl₂·6H₂O and characterized. An X-ray structure determination of the complex has been completed. Average Ni-N and Ni-O distances are, respectively, 1.86(2) Å and 1.849(14) Å. N···N bite distance and bite angle are 2.627(6) Å and 87.2(2)°, respectively, for the five-membered chelate ring. The water molecule forms hydrogen bonds with O atoms of two complex molecules.     

Crystal and molecular structure of [Au(C<Subscript>14</Subscript>H<Subscript>24</Subscript>N<Subscript>4</Subscript>)][H<Subscript>3</Subscript>O](ClO<Subscript>4</Subscript>)<Subscript>4</Subscript>

The crystal and molecular structure of doubly protonated tetraazamacrocyclic complex of gold(III) [Au(C₁₄H₂₄N₄)][H₃O](ClO₄)₄ has been determined. The crystals are monoclinic: a = 11.158(2) Å, b = 8.243(1) Å, c = 14.756(2) Å; β = 98.65(1)°, V = 1341.8(3) ų, Z = 2, ρ(calc) = 1.134 g/cm³, space group P2₁/n. The structure is built of almost flat centrosymmetrical Au(C₁₄H₂₄N₄)]³⁺ and [H₃O]⁺ cations and [ClO₄]^? anions. The gold atom is coordinated with four nitrogen atoms of the ligand forming a flat square. The coordinated ligand is protonated at its γ-carbon atoms of the two six-membered chelate rings. The Au-N bond lengths are almost identical (the mean value is 1.994 Å). The six-membered rings of the complex contain C=N diimine bonds. The [H₃O]⁺ oxonium ion has H-bonds with the oxygen atoms of perchlorate ions.