Crystal structure of the Ni(II) complex with the nitroxyl radical derivative of 3-imidazoline and 1-butanol

The crystal structure was found for the Ni(II) complex with the nitroxyl radical derivative of 3-imidazoline L=C₁₀H₁₃N₂O₂F₃ and 1-butanol C₄H₉OH with the formula NiL₂(n-C₄H₉OH)₂ (a=10.907(2), b=16.769(5), c=12.321(3) Å, =96.33(2), =120.36(1), =106.3(2)^o, V = 1780.7(7) ų, d_calc=1.32 g/cm³, space group P1, Z=2, R=0.072). The structure was molecular in nature. Octahedral coordination of the nickel ion was found with the oxygen and nitrogen atoms of two bidentate L in the equatorial plane [Ni–O, 2.13 Å (av.); Ni–N, 1.99 Å (av.)] and the oxygen atoms [Ni–O_OH, 2.13 Å (av.)] of the OH groups of the alcohol molecules in the axial positions. The rather strong hydrogen bonds between the coordinated OH groups of the alcohol and oxygen atoms of the groups of the adjacent complex molecules (O...O, 2.78–2.84 Å) delineate layers, in which the distances between the paramagnetic sites of adjacent molecules Ni... are shorter than the intramolecular distances and much shorter than the analogous distances between adjacent layers. On the whole, this structure is similar to those of analogous compexes with other alcohols previously studied.Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 2, pp. 119–125, March–April, 1993.     

Synthesis and crystal structure of copper(II) bis-chelate comprising a nitrile derivative of 3-imidazoline nitroxide

Syntheses of a nitroxide radical 2-(1-oxyl-2,2,5,5-tetramethyl-imidazolin-4-yliden)-3-oxo-5-phenylpentannitrile $(HL^{CH_2 CH_2 Ph} )$ and its copper(II) complex are reported. The coordination compound is characterized by the single crystal X-ray diffraction analysis (a = 11.647(2) Å, b = 13.269(3) Å, c = 13.844(3) Å, α = 61.83(2)°, β = 88.13(2)°, γ = 74.12(2)°, space group $P\bar 1$ ). The $Cu(L^{CH_2 CH_2 Ph} )_2 (H_2 O)$ complex has a molecular structure.     

Crystal structure of cobalt(II) complexes with imidazoline nitroxide

The crystal structures of Co(II) coordination compounds CoL ₂-α modification (I), CoL₂(CH₃OH)₂ (II), and CoL₂Py₂(III) — where L is a stable nitroxide 4-(3′,3′,3′-trifluoro-2′-oxypropylene)-2,2,5,5-tetramethyl-3-imidazoline-l-oxyl (L), were determined. It was found that the tetrahedral surroundings of cobalt in I consist of the O and N donor atoms of the deprotonated enaminoketone groups of L. In II and III, the same atoms form the equatorial plane of the centrosymmetric octahedral environment of the central atom in which the axial positions are occupied by the methanol O atoms or the pyridine N donor atoms. In the octahedral coordination centers of II and III, the Co-O and Co-N distances exceed analogous distances in the tetrahedral coordination center of I, substantially increasing the chelate angle in I compared to II and III. In I, the Co-O and Co-N bond lengths and the OCoN chelate angles are, respectively, 1.921(4), 2.006(4) Å, 93.6(2)° in II, 2.014(4), 2.177(4), Co-O_OH 2.146(4) Å, 86.9(2)° in the two crystallographically independent molecules of III, 2.031(2) and 2.022(2), 2.170(2) and 2.193(2), Co-N_Py 2.213(2) and 2.219(2)Å, 87.04(7) and 87.20(7)°. Compounds I and III are molecular. Compound II in the solid state has a layered polymer structure due to hydrogen bonding between the O atoms of the nitroxyl groups of L and the O atoms of the coordinated alcohol molecules.     

Synthesis,crystal structure and magnetic properties of a nickel(II) complex with pyridine-substituted nitronyl nitroxide radicals

The complex [Ni(NIT2Py)(PDA)(H₂O)]·(MeOH)(H₂O) [NIT2Py = 2-(2-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; PDA = 2,6-pyridine dicarboxylic acid] has been prepared and structurally characterized. The Ni^II ion is in a distorted octahedral environment: one nitrogen atom and one oxygen atom from the NIT2Py, one nitrogen atom from the PDA and one oxygen atom from the H₂O in the basal plane; two oxygen atoms from the PDA in the axial position. The units of [Ni(NIT2Py)(PDA)(H₂O)] were connected as a one dimension chain by intermolecular hydrogen bonds. The complex exhibits intramolecular antiferromagnetic interactions between the Ni^II ion and the NIT2Py.     

Crystal structure of a complex of nickel(II) with 2-amino-4-imino-2-pentene

The structure of a nickel(II) complex with 2-amino-4-iminopentane is determined by X-ray crystallography at 150 K. Crystal data for C₁₀H₁₈N₄Ni are: a = 10.9802(3)Å, b = 13.5780(4)Å, c = 8.0935(2)Å, β = 107.304(1)°, space group P2₁/c, V = 1152.04(5) ų, Z = 4, d _x = 1.459 g/cm³, R = 0.0283. The structure is molecular; the metal atom is coordinated by four nitrogen atoms of two β-diimine ligands. The Ni-N distances in Ni(NacNac)₂ fall within 1.8571–1.8623 Å. The molecules in the crystal are joined by only van der Waals interactions.     

Crystal structure and DFT analyses of a pentacoordinated PCP pincer nickel(II) complex

The reaction of NiCl₂ with 1,3‐bis[(diphenylphosphanyl)methyl]hexahydropyrimidine in the presence of 2,6‐dimethylphenyl isocyanide and KPF₆ afforded a new pentacoordinated PCP pincer Ni^II complex, namely {1,3‐bis[(diphenylphosphanyl)methyl]hexahydropyrimidin‐2‐yl‐κN²}(2,6‐dimethylphenyl isocyanide‐κC)nickel(II) hexafluoridophosphate 0.70‐hydrate, [Ni(C₉H₉N)(C₃₀H₃₀ClN₂P₂)]PF₆·0.7H₂O or [NiCl{C(NCH₂PPh₂)₂(CH₂)₃‐κ³P,C,P′}(Xylyl‐NC)]PF₆·0.7H₂O, in very good yield. Its X‐ray structure showed a distorted square‐pyramidal geometry and the compound does not undergo dissociation in solution, as shown by variable‐temperature NMR and UV–Vis studies. Density functional theory (DFT) calculations provided an insight into the bonding; the nickel dsp²‐hybridized orbitals form the basal plane and the nearly pure p orbital forms the axial bond. This is consistent with the NBO (natural bond orbital) analysis of analogous nickel(II) complexes.     

Synthesis and crystal structures of the nickel(II) complex with nitronyl nitroxide

Two nickel(II) complexes [Ni(NIT-l′-MeBzlrn)₂(Dca)₂] (I, II) (NIT-l′-MeBzIm = 2-{2′-[(l′methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide) have been prepared and structurally characterized by single-crystal X-ray diffraction. They are structural epimers. The complexe crystallizes in monoclinic, space group P2₁/n, Z = 4. Crystal data: C₃₄H₃₈N₁₄NiO₄, M _r = 765.49, a = 15.019(3), b = 18.803(4), c = 15.756(3) Å, β = 109.399(3)°, γ = 90° (I); a = 13.934(3), b = 11.046(2), c = 24.570(5) Å, β = 90.024(2)° (II). The X-ray analysis reveals that Ni²⁺ ion resides in a distorted octahedral center. The complex was linked by intermolecular hydrogen bonds, resulting in a ID chain structure for I and a 2D network configuration for II.     

Crystal structure of a nickel(II) complex with the macrocyclic ligand 4-methyl-1,3,5,8,11,14-hexaazatricyclooctadecane

The crystal structure of the macrocyclic complex [Ni(PCHA)](ClO₄)₂ (II) (PCHA = 4-methyl-1,3,5,8,11,14-hexaazatricyclooctadecane) is described. In the presence of succinate acid, [Ni(PCHA)](ClO₄)₂ (II) is obtained by recrystallization of orange crystals of [Ni(PCHA)](ClO₄)₂ (I), whose structure has previously been identified. The [Ni(PCHA)](ClO₄)₂ (II)crystal belongs to the monoclinic P2(1)/c space group with a = 15.8561(3) ?, b = 9.4409(2) ?, c = 13.9297(2) ?, α = 90°, β = 94.8840(10)°, γ = 90°, M _r = 526.02, Z = 4, V = 2077.65(7) ?³. The structure is ionic with [Ni(L)]²⁺ and two perchlorate anions with a supermolecular interaction.     

Crystal structure of a Mn(II) complex with isatin-hydrazone-S-benzyldithiocarbazate

The reaction of Mn(OAc)₂·4H₂O with isatin-hydrazone-S-benzyldithiocarbazate (HIsa-SBn) results in the formation of a bis-ligand complex [Mn(Isa-SBn)₂]·2DMF. Its single crystal is obtained and the structure is determined by X-ray diffraction. It belongs to a monoclinic space group C2/c with the cell parameters: a = 23.290(4) Å, b = 11.4980(18) Å, c = 18.483(5) Å, V = 4087.6(14) ų. The Mn(II) atom is six-coordinated with two amide O atoms, two azomethine N atoms, and two thiolate S atoms, resulting in a distorted octahedral geometry.     

Crystal structure and magnetic properties of the octahedral complexes of Ni(II) with 3-imidazoline nitroxides

This paper reports on our studies of the crystal structures and magnetic properties of five mixed-ligand octahedral complexes of Ni(II) with 3-imidazoline nitroxides Ni(RL)₂X₂, where RL are deprotonated enaminoketone derivatives of 3-imidazoline nitroxide with different substituents R (CF₃, Ph) in the side chain, and X is pyridine, dimethylsulfoxide, or semi-phenanthroline. It is established that this type of heterospin system is characterized by an intramolecular exchange interaction parameter (J) of an order of 10 cm⁻¹. Substitution of the N-donor diamagnetic pyridine or phenanthroline by the O-donor dimethylsulfoxide in the coordination sphere of the metal decreases J by 2–3 cm⁻³. A transition from trans-to cis-coordination of the enaminoketone ligands and variation of the R substituent in the chelate ring do not affect the value of J. Deceased. Translated fromZhurnal Struktumoi Khimii, Vol. 39, No. 5, pp. 901–916, September–October, 1998. This work was supported by INTAS grant No. 94-3508 and RFFR grants No. 96-03-33738 and 96-03-32229.     

Synthesis,crystal structure and magnetic properties of a nickel(II) complex containing a 2-pyridyl-substituted nitronyl nitroxide

A new complex of formula [Ni(NIT2Py)₂Cl(H₂O)]Cl·2CH₃OH, where NIT2Py is 2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, was synthesized and characterized structurally and magnetically. The structure consists of a [Ni(NIT2Py)₂Cl(H₂O)]⁺ ion, a chloride anion and two methanol molecules. The nickel(II) ion lies in a distorted octahedral environment; two nitrogen atoms and two oxygen atoms from NIT2Py ligands from the basal plane; one oxygen atom from a water molecule and one chloride anion occupy axial positions. Variable temperature magnetic susceptibility data show that there is strong antiferromagnetic coupling between the nickel(II) ion and nitronyl nitroxide radicals. The results suggest that the sign of the magnetic interaction depends on structural and ligand effects.     

A dimeric high-spin nickel(II) compound with a transition to monomeric tetrahedral nickel(II)

Summary The synthesis and characterisation of dichloro[bis(3,5-dimethylpyrazolyl)methane]nickel(II) s described. At ambient temperature the compound is dimeric with chloro-bridged high-spin five-coordinate Ni^II     

Layer polymeric Cu(II) complexes with enaminoketone derivatives of 3-imidazoline nitroxide. First structurally defined CuBr2 complex with imidazoline zwitterion

Crystal stmctures of two layer polymeric hetcrospin complexes Cu(L^Hal,R )₂ , where L are deprotonated enaminoketone derivatives of a stable radical 3-imidazoline nitroxide (Hal = Cl, R = CF₃ and Hal = Br, R = COOC₂H₅), are described. In the solid state, both compounds have a layer polymeric structure with Cu(11) ions coordinating the O atoms of the nitroxyl groups of the neighboring molecules. The stmcture of the product of decomposition of Cu(L^Br,COOC ₂H_{5 2} — Cu(L′)₂Br₂ · 2H₂O—which is a rare example of a complex with a coordinated zwitterion (4-carboxy-2,255-tetramethyl-3-imidazoline zwitterion), is analyzed. Translated fromZhumal Struktunoi Khimii, Vol. 41, No. 2, pp. 349–358, March–April, 2(XX).     

Crystal structure of bis(iso-maleonitril-edithiolate)nickel(II) benzylpiperidinium

Bis(iso-maleonitriledithiolate)nickel(II) benzylpiperidinium, [BzPid]₂[Ni(i-mnt)₂] (1) is prepared and characterized by elemental analyses, UV, IR, molar conductivity, and single crystal X-ray diffraction. It is found that 1 crystallizes in the monoclinic space group P2₁/n with a = 9.551(1) Å, b = 16.520(2) Å, c = 11.004(1) Å, β = 96.60(1)°, V = 1724.6(3) ų, Z = 2. Consolidate the stacking of the molecules The electrostatic interaction between [Ni(i-mnt)₂]^2? anions and [BzPid]⁺ cations consolidates the stacking of the molecules.     

Crystal structure of a new copper(II) complex with borodicitric acid

The crystal structure of the double copper(II) complex with borodicitric acid [Cu(H₂O)₅(C₆H₆O₇)₂B]⁺ · [(C₆H₆O₇)₂B]^? · 5H₂O of composition Cu[(C₆H₆O₇)₂B]₂ · 10H₂O has been studied by X-ray crystallography. The crystals are monoclinic, space group P2₁): a = 10.7852(2) ?, b = 9.9980(2) ?, c = 17.9500(5) ?; ?? = 101.126(1)°, FW = 1025.75, V = 1899.18(7) ?³, Z = 2. The dicitratoborate anions with a spirane structure have a normal geometry. The coordination polyhedron of the copper atoms is a distorted octahedron (CN 6 = 4 + 2) with an average equatorial Cu-O distance of 1.965 ± 0.023 ?. The axial positions in the CuO₆ octahedron are occupied by a water molecule and an oxygen atom of one of the citrate ligands: Cu-O(5w), 2.430(3) ?; Cu-O(8), 2.382(3) ?. The crystals have an extended intricate system of hydrogen bonds consisting of 27 unique three-center O-H??O, O(w)??O, and O(w)??O(w??) bonds and four-center O(w)??O, O(w??) bonds with different structural functions.