Structure and magnetic properties of monophenylphosphinate bridged chain polymers of manganese(II), [MnL2(HPhPO2)2]x (where L = HPhPO2H, CH3CONH2, H2O, HCONH(CH3), and C5H5N)

1992 ◽  
Vol 70 (3) ◽  
pp. 732-741 ◽  
Author(s):  
Jing-Long Du ◽  
Steven J. Rettig ◽  
Robert C. Thompson ◽  
James Trotter ◽  
Peter Betz ◽  
...  

Crystals of Mn(CH3CONH2)2(HPhPO2)2 are monoclinic, a = 5.668(2), b = 7.500(2), c = 23.104(2) Å, β = 95.52(2)°, Z = 2, space group P21/c, and those of Mn(HPhPO2H)2(HPhPO2)2 are monoclinic, a = 23.281(1), b = 5.508(2), c = 20.5489(6) Å, β = 90.424(4)°, Z = 4, space group C2/c. The structures were solved by heavy-atom methods and were refined by full-matrix least-squares procedures to R = 0.028 and 0.035 for 2081 and 2117 reflections with I ≥ 3σ(I), respectively. Both compounds have structures consisting of polymeric chains propagating along the crystallographic b axis; two phosphinate ligands bridge adjacent manganese atoms forming square planar MO4 units, and six coordination about the metal is achieved by axially O-bonded neutral ligands. Indirect evidence supports similar structures for the other complexes studied here. The complexes are antiferromagnetic and the magnetic susceptibilities have been analyzed according to two Heisenberg models for linear chains. The exchange coupling constants range from −0.30 cm−1 for the acetamide complex to −0.06 cm−1 for the pyridine complex. Magnetostructural correlations involving these complexes and the previously studied Mn(HCONH2)2(HPhPO2)2, reveal that the magnitude of the magnetic coupling is enhanced by symmetrically bridging O—P—O units and short Mn–O–P–O–Mn pathways for exchange. Keywords: polymeric manganese monophenylphosphinates, crystal structures, magnetic properties.

1991 ◽  
Vol 69 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Jing-Long Du ◽  
Steven J. Rettig ◽  
Robert C. Thompson ◽  
James Trotter

The synthesis of the β and γ forms of M(Ph2PO2)2 where M = Co and Mn are described and the compounds are characterized by infrared spectroscopy, differential scanning calorimetry, X-ray powder diffraction, and low-temperature (2–80 K) magnetic susceptibility studies. Single crystal X-ray diffraction studies are reported on the γ forms. Crystals of the γ forms of poly-bis(μ-diphenylphosphinato)cobalt(II) and poly-bis(μ-diphenylphosphinato)manganese(II) are isomorphous, crystallizing with 4 formula units per unit-cell in the monoclinic space group P21/c. Lattice constants are a = 8.080(2), 8.161(1), b = 23.550(6), 23.751(1), c = 11.726(3), 11.6946(6) Ǻ, and β = 92.88(2), 93.026(8)° for the Co and Mn derivatives respectively. The structures were solved by heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.039 and 0.045 for 4041 and 2878 reflections with I ≥ 3σ(I), respectively. Both crystal structures consist of double phosphinate-bridged chain polymers containing tetrahedrally coordinated metal atoms: Co—O = 1.950(2)–1.963(2) Ǻ, O—Co—O = 104.81(8)–117.77(9)°, Mn—O = 2.016(3)–2.033(3) Ǻ, O—Mn—O = 103.2(1)–114.7(1)°. All four compounds exhibit antiferromagnetic coupling and magnetic susceptibilities have been analyzed according to two Heisenberg models for linear chains of metal ions with S = 3/2 for cobalt and S = 5/2 for manganese. The Weng model (with values for the Wagner and Friedberg model in parentheses) gives –J = 0.25 (0.26) cm−1 and 0.55 (0.60) cm−1 for the β and γ forms, respectively, of Co(Ph2PO2)2, and 0.34 (0.36) cm−1 and 0.17 (0.17) cm−1 for the β and γ forms, respectively, of Mn(Ph2PO2)2. Key words: crystal structure, diphenylphosphinates of cobalt(II) and manganese(II), magnetic properties.


1984 ◽  
Vol 62 (6) ◽  
pp. 1057-1067 ◽  
Author(s):  
Brenda M. Louie ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter

The synthesis and characterization of the complexes [Me2Gapz2]Rh(LL) (where LL = COD, (CO)2, (PPh3)2, or (PPh3)(CO)), incorporating the bidentate, chelating, dimethylbis(1-pyrazolyl)gallate ligand are described. Non-rigidity in solution has been demonstrated by 1H nmr studies for some of the complexes. A crystal structure determination of the COD complex has confirmed the boat conformation for the Ga—(N—N)2—Rh six-membered ring in this complex in the solid state. In addition, the solid state structures of the 3,5-dimethylpyrazolyl bridged dirhodium complexes [Rh(μ-3,5-Me2pz)(CO)2]2 and [Rh(μ-3,5-Me2pz)(COD)]2 have been determined. Crystals of [Me2Gapz2]Rh(COD) are orthorhombic, a = 22.7447(8), b = 11.9776(5), c = 6.4635(3) Å, Z = 4, space group Pnma; those of [Rh(μ-3,5-Me2pz)(CO)2]2 are monoclinic, a = 8.7403(6), b = 16.3594(6), c = 25.434(2) Å, β = 95.286(3)°, Z = 8, space group P21/c; and those of [Rh(μ-3,5-Me2pz)(COD)]2 are triclinic, a = 10.350(2), b = 11.401(2), c = 12.355(2) Å, α = 112.485(7), β = 99.394(9), γ = 105.387(8)°, Z = 2, space group [Formula: see text]. All three structures were solved by conventional heavy atom techniques and were refined by full-matrix least-squares procedures to final conventional R values of 0.026, 0.024, and 0.037 for 1824, 5135, and 6109 reflections with I ≥ 3σ(I), respectively. In each case the Rh atoms have distorted square planar coordination geometry. Important mean structural parameters are Rh—N = 2.087(2), Rh—C = 2.129(2), [Formula: see text] for [Me2Gapz2]Rh(COD); Rh—N = 2.063(6), Rh—CO = 1.852(9), [Formula: see text] for [Rh(μ-3,5-Me2pz)(CO)2]2; and Rh—N = 2.084(1), Rh—C = 2.131(7), [Formula: see text] for [Rh(μ-3,5-Me2pz)(COD)]2.


1981 ◽  
Vol 36 (4) ◽  
pp. 441-446 ◽  
Author(s):  
Frank Kübel ◽  
Joachim Strähle

Abstract Polymeric bis(dimethyl-and diphenylglyoximato)-complexes of Fe(II) and Co(II) with pyrazine as a bridging ligand have been synthesized. The Co(II) complexes are para-magnetic with μ = 1.83 B.M., and surprisingly stable against oxidation. Bis (dimethyl-glyoximato)pyrazine-cobalt (II) crystallizes monoclinic in the space group C2/m with Z = 2. The crystal structure shows linear chains of alternating Co atoms and pyrazine ligands. Perpendicular to the chain, the Co atoms are coordinated in a square planar arrangement by two dimethylglyoximato ligands (Co-N= 189 pm), the local symmetry being C2h-The long Co-pyrazine distance of 224 pm is in agreement with the fact that the compound is a 19 electron complex. The Co complexes do not have conducting properties. The Fe(II) complexes possess the same structure but with stronger bonds in the chain. They show very low conductivity of approximately 10-10 cm -1 Ω-1 . The Mössbauer spectra of the Fe-complexes are reported.


1985 ◽  
Vol 63 (11) ◽  
pp. 3019-3026 ◽  
Author(s):  
Brenda M. Louie ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter

The syntheses and characterization of a number of square-planar Rh(I) monocarbonyl complexes incorporating un-symmetrical, tridentate, pyrazolylgallate ligands in a meridional coordination mode are described. Oxidative addition reactions of these complexes are detailed and a facile migratory insertion reaction, following the addition of methyl iodide, has resulted in a five-coordinate square-pyramidal Rh(III) acetyl complex. Crystal structures of two compounds are presented, [Me2Gapz(OCH2CH2NH2)]Rh(CO) and [Me2Gapz(OCH2CH2NMe2)]Rh(COMe)I, and confirm the molecular arrangements predicted on the basis of other physical measurements. Crystals of the former are monoclinic, a = 10.212(2), b = 7.8484(5), c = 16.733(2) Å, β = 105.133(6)°, z = 4, space group P21/c; and those of the latter are monoclinic, a = 10.0960(11), b = 11.5352(8), c = 15.871(2) Å, β = 105.764(6)°, z = 4, space group P21/n. Both structures were solved by conventional heavy atom methods and were refined by full-matrix least-square procedures to R = 0.026 and 0.036, respectively, for 2142 and 2941 reflections with I ≥ 3σ(I).


1986 ◽  
Vol 64 (3) ◽  
pp. 566-574 ◽  
Author(s):  
David A. Cooper ◽  
Steven J. Rettig ◽  
Alan Storr

The reaction of the [Rh(CO)2Cl]2 dimer with the Na+[Me2Ga(N2C3H3)(OCH2(C5H4N))]− ligand has yielded the planar four-coordinate species [Me2Ga(N2C3H3)(OCH2(C5H4N))]Rh(CO), (LRh(CO)), displaying the tridentate gallate ligand in a meridional coordination mode. In addition, a second product, of similar geometry but with one of the Me groups on the Ga replaced by a Cl atom, viz, [(Cl)MeGa(N2C3H3)(OCH2(C5H4N))]Rh(CO), has also been isolated and characterized. The former complex undergoes a facile oxidative addition reaction with MeI, the transient six-coordinate Rh(III) species produced being rapidly converted, in a methyl migration step, to the five-coordinate Rh(III) acetyl complex, LRh(COMe)I. Crystals of [Me2Ga(N2C3H3)(OCH2(C5H4N))]Rh(CO) are monoclinic, a = 13.139(2), b = 13.324(2), c = 17.352(2) Å, β = 103.251(7)°, Z = 8, space group I2/a, and those of [(Cl)MeGa(N2C3H3)(OCH2(C5H4N))]Rh(CO) are triclinic, a = 8.846(2), b = 12.714(3), c = 7.631(2) Å, α = 93.82(1), β = 113.94(1), γ = 107.99(1)°, Z = 2, space group [Formula: see text] Both structures were solved by conventional heavy-atom methods and were refined by full-matrix least-squares procedures to final R values of 0.029 and 0.048 for 1890 and 1939 reflections with I ≥ 3σ(I), respectively. Both molecules display irregular square planar coordination geometry about Rh with Rh—O = 2.038(3) and 2.048(3), Rh—N(pyrazolyl) = 2.022(4) and 2.025(7), Rh—N(pyridyl) = 2.038(3) and 2.020(6), Rh—CO = 1.778(5) and 1.808(9) Å, respectively, for the two compounds. Molecules of [Me2Ga(N2C3H3)(OCH2(C5H4N))]Rh(CO) form weakly associated, centrosymmetric dimers via an intermolecular [Formula: see text] interaction of 3.5445(7) Å.


1982 ◽  
Vol 35 (11) ◽  
pp. 2193 ◽  
Author(s):  
GL Roberts ◽  
BW Skelton ◽  
AH White ◽  
SB Wild

The potentially tridentate chelating agent bis(6-methylquinolin-8-yl)phenylarsine (AsN2) and quadridentate tris(6-methylquinolin-8-yl)arsine (AsN2) have been prepared from 6-methyl-8-lithio-quinoline and dichlorophenylarsine or arsenic trichloride, respectively. Both ligands behave as bidentates in complexes of the type [PdX2(AsN2)] and [PdX2(AsN2)] (where X = Cl or I) and as tridentates in [Mo(CO)3(AsN2)] and [Mo(CO)3(AsN2)]. The crystal and molecular structures of [PdCl2(AsN2)],CH2Cl2 and [PdI2(AsN2)] have been determined by single-crystal X-ray analysis. The dichloro complex crystallizes in space group P1 (Ci1; No.2) with a 9.963(3), b 8.555(3), c 16.102(7) �; α 86.64(3), β 82.13(3), γ 85.84(3)�; U 1354.3(9) �3 and Z = 2. The structure was solved by heavy-atom methods and refined by least squares to R 0.044 for 2530 'observed' reflections with 1>3σ(I). The coordination geometry of the palladium(II) atom is pseudo-square-planar in which the potentially tridentate AsN2 is behaving as a bidentate only. There is no evidence of interaction of the remaining 6-methylquinolin-8-yl group with the metal centre, although a weak interaction between the solvent of crystallization and the metal may be present. The diiodo complex similarly crystallizes in the centrosymmetric triclinic space group P1 (Cil ; No.2) with a 13.590(5), b 10.035(2), c 9.435(2) �; α 102.68(2), β 90.10(2), γ 92.99(2)�; U 1253.5(6) �3 and Z = 2. Least- squares refinement led to a convergence with R 0.038 for 3461 'observed' reflections. The structure of this complex was similar to that of the dichloro analogue.


1998 ◽  
Vol 53 (11) ◽  
pp. 1281-1284 ◽  
Author(s):  
Manas Kumar Saha ◽  
Sutapa Sen ◽  
Parimal Kundu ◽  
Tarakranjan Gupta ◽  
Volker Gramlich ◽  
...  

[LCu{μ-(OH)2(C2O2)}CuL](ClO4)2, (HL = N,N-dimethyl N-propylsalicylald-imine) was synthesised and its crystal structure was determined. C26H36CI2Cu2N4O14, triclinic space group P1̅ with a = 9.288(9), b = 10.016(11), c = 10.09(2) Å and a = 101.05(11), β = 108.22(10), γ = 110.22(10)°, V = 787(2) Å3, Z = 2. Two copper(II) ions in a distorted square-planar coordination are bridged by an oxalic acid molecule to form dinuclear units. The copper(II) centres are separated by 5.2 Å and antiferromagnetically coupled (J = -478 cm-1), which follows from temperature-dependent magnetic susceptibility measurements in the range 12 to 300 K.


1997 ◽  
Vol 52 (2) ◽  
pp. 157-161 ◽  
Author(s):  
Ayhan Elmali ◽  
Yalcin Elerman ◽  
Ingrid Svoboda ◽  
Hartmut Fuess ◽  
Klaus Griesar ◽  
...  

Abstract [Cu2L] (L=N-2-hydroxy-4-methylphenyl-4-oxo-2-pentalketimine) was synthesized and its crystal structure determined. C24H26Cu2N2O4 monoclinic space group P21/n with a= 10.978(2), 17.045(3), c= 11.958(2) Å, β = 101.89(1)°, V = 2189.6(7) Å3,Z = 4. Two copper(II) atoms in a distorted square-planar coordination are bridged by two oxygen atoms to form a dinuclear unit. The copper(II) centers are separated by 3.025(1) Å and antiferromagnetically coupled (J =-222.3 cm-1 ), which follows from temperature-dependent magnetic susceptibility measurements in the range 4.2 to 300 K.


1985 ◽  
Vol 63 (2) ◽  
pp. 503-508 ◽  
Author(s):  
Brenda M. Louie ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter

Details of the synthesis and physical properties of [Me2Ga(3,5-Me2pz)2]Rh(CO)PPh3 are given. Crystals of [dimethylbis(3,5-dimethyl-1-pyrazolyl)gallato-N,N′](triphenylphosphine)carbonylrhodium(I) – toluene (1:1) are triclinic, a = 10.690(2), b = 12.928(2), c = 13.998(2) Å, α = 77.44(1), β = 83.50(1), γ = 72.70(1)°, Z = 2, space group [Formula: see text]. The structure was solved by conventional heavy-atom methods and was refined by full-matrix least-squares procedures to R = 0.039 and Rw = 0.048 for 5987 reflections with I ≥ 3σ(I). The Rh(I) is in a distorted square planar environment with Rh—N = 2.090(3) and 2.097(2), Rh—CO = 1.815(4), and Rh—P = 2.2700(8) Å. The central six-membered RhGaN4 ring has a steep boat conformation with a [Formula: see text] separation of 3.3819(4) Å.


1992 ◽  
Vol 57 (11) ◽  
pp. 2309-2314 ◽  
Author(s):  
Josef Loub ◽  
Zdeněk Mička ◽  
Jana Podlahová ◽  
Karel Malý ◽  
Jürgen Kopf

Structure of sodium hydrogen selenite-selenious acid (1:3) was solved by heavy-atom method and refined anisotropically to R = 0.098 for 1223 unique observed reflections. The title compound crystallizes in the Pc space group with a = 5.756(2), b = 4.911(2), c = 20.010(5) Å, β = 100.48(3)°, V = 556(1) Å3, T = 293 K, (a = 5.763(2), b = 4.878(1), c = 20.03(1) Å, β = 100.48(3)°, V = 554(1) Å3, T = 173 K), Z = 2. The structure consist of HSeO3- anions, molecules of selenious acid and Na+ cations which are octahedrally coordinated with oxygen atoms. The structure is stabilized by a system of hydrogen bonds.


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