Ruiwu Wen

Synthesis and Characterization of Nitrato-Triamine-Metal(II) Complexes. Conglomerate Crystallization Part 55. Crystal Structure of [Ni(dien)(O2NO)(ONO2)] (I), {[Cu(dien)-(μ-ONO2)]NO3}∞ (II), [Zn(dien)(O2NO)(ONO2)] (III), [Ni(Medpt)(O2NO)(ONO2)] (IV) and [Cu(Medpt)(ONO2)2] (V)

In absolute ethanol and in the presence of triethylorthoformate, reactions of metal(II) nitrates with linear tridentate amines afforded metal complexes of the formula M(NNN)(NO3)2, where M = Ni2+, Cu2+ and Zn2+, and NNN = dien and Medpt. The compounds fall into three categories in accordance with their stereochemistry and mode of binding of the nitrato ligands. Compounds I, [Ni(dien)(O2NO)(ONO2)] and III, [Zn(dien)(O2NO)(ONO2)] are isomorphous and isostructural. They crystallize in the monoclinic space group P21/n with nearly identical cell constants. The stereochemistry of these two compounds is such that the terdentate dien ligand forms a fac MN3 moiety with the two oxygens of the bidentate nitrato ligand trans to the terminal NH2. These ligands form the base of the octahedral arrangement in which the sixth position, trans to the secondary nitrogen of the dien, is an oxygen of the monodentate nitrato ligand. Compound IV, [Ni(Medpt)(O2NO)(ONO2)] falls into the same category as I and III despite the fact that the two rings in the Ni-Medpt moiety are six-membered rings, unlike those in compounds I and III which are five-membered rings. Nevertheless, the nickel-amine arrangement is fac. The bidentate nitrato-oxygens are trans to the terminal NH2 of the amine ligand, and the oxygen of the monodentate nitrato ligand is trans to the tertiary amine-nitrogen. Such stereochemistry is prevalent for nickel and zinc compounds. Interestingly, compound IV crystallizes as a conglomerate (space group P212121). Compound II, {[Cu(dien)(μ-ONO2)]NO3}∞ belongs to the second category and has a polymeric structure. The repeating fragment in the polymeric chain is a Cu(dien)-O fragment with the monodentate nitrato ligand occupying an equatorial position of the base. A second oxygen of the equatorial nitrate becomes an axial ligand for an adjacent Cu-N3O fragment. In this way the substance propagates into an infinite chain. The repeating unit has an effective square pyramidal, five-coordinate, configuration. Finally, the compound crystallizes as a racemate. The second nitrate necessary for charge compensation of this copper(II) compound is ionic and its function is to hold the infinite chains of the lattice. The third category represented by compound V, [Cu(Medpt)(ONO2)2] contains two molecules in the asymmetric unit of the racemic lattice (monoclinic, space group P21/a). The structure of Cu-Medpt is unlike that of IV in that both species present in the asymmetric unit have the amine ligand in a mer configuration which together with a monodentate oxygen of a nitrato ligand form a base plane of a square pyramid. The fifth ligand of both Cu2+ ions is a second monodentate nitrato ligand. The stereochemical differences between the two Cu2+ ions are insignificant for the Cu-Medpt fragment, which share the same conformation and configuration. The major difference between the two species is the torsional angles defined by the Cu-O-N-O angles. The difference arises from variation in the hydrogens of the primary amine moieties selected by nitrato-oxygens to form intramolecular hydrogen bonds. Finally, there is a little variation in the equatorial Cu-ONO2 stereochemistry because of steric hindrance, imposed by the Medpt, preventing large torsional angles by these nitrato ligands. This is evident by comparing the two copper species shown in Finally, nitrate-to-Br ligand exchange was found to take place when KBr pellets are prepared for IR spectral measurements.

The phenomenon of conglomerate crystallization ☆: Part 52. Stereochemical control of the crystallization pathway by small alterations of ligands

Abstract The X-ray structure analysis of mer-trans-[Co(aepn)Cl2(OH2)](ClO4)·H2O (1) (aepn=N-(2-aminoethyl)-1,3-propanediamine) reveals that the compound crystallizes in an enantiomorphic space group P212121 implying a spontaneous resolution of its racemic solution, known as conglomerate crystallization. Substitutions of the two chloride ligands with bromides result in the isostructural compound mer-trans-[Co(aepn)Br2(OH2)](ClO4)·H2O (2), which also crystallizes as a conglomerate in the space group P212121. Meanwhile, a substitution of the coordinated OH2 of 1 with NH3 gives mer-trans-[Co(aepn)Cl2(NH3)](ClO4) (3), which crystallizes as a simple racemate in P21/n space group. When N-(3-aminopropyl)-1,3-propanediamine (dpt) is used instead of aepn in the preparation of 1, it gives racemic crystals of mer-trans-[Co(dpt)Cl2(OH2)](ClO4) (4) whose molecular packing pattern is identical to that of 3. In the conglomerate structures, the protons of coordinated water ligand are strongly hydrogen-bonded to the oxygen of a water of crystallization to form a spiral packing structures. In the packing structures of 3 and 4, two molecules of opposite chirality are brought together around a crystallographic center of inversion by hydrogen bonds of the protons of the corresponding tridentate amine ligand with oxygens of perchlorate anion.

CONTROL OF THE COORDINATION MODE OF NO2 − BY THE NATURE OF THE AMINE LIGAND. CRYSTAL STRUCTURE OF THE NEUTRAL ZIGZAG POLYMERIC COMPOUND [mer-Ni(N-(2-Aminoethyl)-1,3-Propanediamine)-(NO2)2] (I)

Abstract A polymeric zigzag complex, [mer-Ni(N-(2-aminoethyl)-l,3-propanediamine)(NO2)2] (I), containing a bridging u-nitro(N,0), was obtained and its crystal structure was determined. Magnetic studies show the compound is antiferromagnetic. These results contrast to those for [Ni(3,3′-diamino-N-methyldipropylamine)(NO2)2] (II), which is a monomer.

CRYSTAL STRUCTURES OF [Ni(en)2(N02)]Cl (I) AND [cis-β-Ni(trien)(NO2)]ClO4 (II)

Abstract Compound (I) [Ni(en)2(NO2)]Cl, NiC4ClH16N5O2, has been synthesized and its crystal structure determined at 100 K. This compound crystallizes from a deionized water solution at 25°C. in the orthorhombic system space group Fdd2 (No. 43) with lattice constants: a = 18.219(3), b = 8.841(2), c = 12.924(1)A, V = 2081.6(5)A3 and MW = 260.37, Z = 8 d = 1.662mgm−3. A total of 3239 data were recorded over the range of 4° ≤ 2θ ≤ 60° of these, 3086 (unique and with I > l[sgrave](I)) were used in the structural analysis. Data were corrected for absorption. The final discrepancies in the refinement of the structure are RF = 0.057 and Rw = 0.072. Compound (II) [Ni(trien)(NO2)]C104, NiC6ClH18N5O6, has been synthesized and its crystal structure determined at room temperature. This compound crystallizes from a deionized water solution at 25°C, in the monoclinic system space group P21/n (No. 14) with lattice constants: a = 8.934(3), b = 12.705(8), c = 12.522(9)A, β = 90.33(4), V = 1421.4(14)A3 MW = 350.40, Z = 4, d...

Control of the coordination mode of NO2 − by the nature of the amine ligand: the importance of H-bond. Crystal structures of the [mer-Ni(dpt)(NO2)2] (I) and [trans-Ni(333-tet)(NO2)2] (II)

Two new nickel(II) amine nitrite compounds were obtained and crystal structures were determined. The compound [ mer -Ni(dpt)(NO 2 ) 2 ] ( I ), which crystallizes in the monoclinic system space group P 2 1 / a , is a polymer and there is only one nickel moiety within an asymmetric unit. Each nickel atom is in an octahedral coordination environment and coordinated by three nitrogens of the amine ligand, one nitrogen of nitro(N) group, one nitrogen of a μ-nitro(N,O), and one oxygen of a μ-nitro(N,O) group. The mononuclear compound [Ni(333-tet)NO 2 ) 2 ] ( II ) crystallizes in space group P . Compound II is neutral, mononuclear, with two nitrite ligands bonded to the central nickel atom through their nitrogens, and located in positions trans to each other. The factors affecting the nitrite coordination mode are discussed. Intra- and/or inter-molecular hydrogen bonds are proposed to be one of the important factors in determining bonding modes and selection of crystallization pathways.

THE PHENOMENON OF CONGLOMERATE CRYSTALLIZATION. PART 53. THE CRYSTALLIZATION BEHAVIOR OF TWO COBALT(III) CARBONATO AMINE COMPOUNDS

Abstract Two new cobalt(III) carbonato amine compounds were synthesized, and their crystal structures were determined. Compound (I), Na2[Co(tren)(CO3)]2(CIO4)4·3H2O, Co2C14CI4H42N8Na2O 25, crystallized as a racemate in the orthorhombic system, space group Pcab (No. 61). The cell dimensions, obtained from the centering of 25 reflections, are a = 10.684(5)å, b = 18.559(8)å, c = 37.528(10)å, V= 7441(5)å3. FW= 1028.18, Z= 8, F(000) = 4203.87, dc = 1.836 Mg·m−3, μ = 1.30 mm−3, λ = 0.70930å. A total of 3457 data were collected over the range of 4° ≤2θ ≤40°; of these, 2377 (independent and I≥2.5σ(I)) were used in the structural analysis. The final RF and Rw residuals were 0.055 and 0.064. Compound (II), [cis-β-Co(trien)(CO3)](HCO3)· H2O, CoC8H21N4O7, crystallized as a conglomerate in the orthorhombic system, space group P212121 (No. 19). The cell dimensions, obtained from the centering of 25 reflections, are a = 8.869(4)å, b = 12.032(8)å, c = 12.522(7)å, V = 1336(1)å3. FW = 344.20, Z = 4, F(000) = 713.62, dc = 1.701 Mg·m−3, μ = 1.32mm−1, λ = 0.70930å. A total of 3504 data were collected over the range of 4° ≤2θ ≤40°; of these, 2497 (independent and I≥ 2.5σ(I)) were used in the structural analysis. The final RF and Rw residuals were 0.049 and 0.059.

THE CRYSTALLIZATION BEHAVIOR OF [cis-α-Co(trien)(OX)lCl 2H2O (I), [cis-α-Co(trien)(NO2)2]BF4 (II), [cis-α-Co(trien)(NO2)2]-(cis-α-Co(trien)(OX)]Cl l/2SiF6 (III)

Abstract Three new compounds were synthesized and their crystal structures determined. For compound (I). [cis-α-Co(trien)(OX)]Cl 2H2O, CoClO6N4C8H22, triclinic, space group P-l (No. 2) a = 6.980(5), b = 8.801(4), c = 12.554(8) A, α = 89.07(5)°, [btilde] = 75.74(4)°, γ = 81.44(5)°, V = 738.9(8) A3, cell dimensions were obtained from 24 reflections giving FW = 364.4, Z = 2, F[000) = 380.06, Dcalc=1.634mg m-3, μ = 1.36mm-1. A total of 1907 data were collected over the range of 4° ≤ 2θ ≤ 45°; of these, 1647 (independent and I≥3σ(I)) were used in the structure analysis. Data were corrected for absorption; transmission coefficients ranged from 0.51754 to 0.73648. The final RF and Rw residuals were 0.033 and 0.042. For compound (II), [cis-α-Co(trien)(NO2)2]BF4, CoN6C6O4BF4H18, orthorhombic space group Pbca (No. 61) α= 12.260(10), b=12.880(14), c= 17.940(14)A F=2833(4)A3, cell dimensions were obtained from 24 reflections with 2θ in the range of 4.00–45.00 degrees, FW = 383.98, Z = 8, F(000) = 1571.52, Dcalc= 1.80...