Synthesis of meso-phenyl-4,6-dipyrrins, preparation of their Cu(II), Ni(II), and Zn(II) chelates, and structural characterization of bis[meso-phenyl-4,6-dipyrrinato]Ni(II)

1996 ◽  
Vol 74 (11) ◽  
pp. 2182-2193 ◽  
Author(s):  
Christian Brückner ◽  
Veranja Karunaratne ◽  
Steven J. Rettig ◽  
David Dolphin
Keyword(s):  
Dihedral Angle ◽  
Direct Methods ◽  
Metal Chelates ◽  
Central Metal ◽  
Full Matrix ◽  
X Ray ◽  
X Ray Crystallography ◽  
Transition Metal Chelates ◽  
Square Planar

meso-Phenyldipyrromethanes can be oxidized by 2,6-dicyano-3,5-dichloro-para-benzoquinone (DDQ) to the corresponding meso-phenyldipyrrins. As expected, these novel, stable bipyrrolic pigments readily form metal chelates with copper(II), nickel(II), and zinc(II). Their UV–VIS spectra are compared with a series of known alkyl-substituted dipyrrin chelates and, based on the UV–VIS spectral analysis, the dihedral angle between the two ligands in the bis[meso-phenyldipyrrinato]Ni(II) complex was calculated to be 42°. The molecular structure of this complex was determined by X-ray crystallography, essentially confirming the calculation. Crystals of C30H22N4Ni are orthorhombic, a = 17.156(3), b = 35.217(1), c = 7.886(1) Å, Z = 8, space group Fddd. The structure was solved by direct methods and refined by full-matrix least-squares procedures to R = 0.040 and Rw = 0.031 for 1058 reflections with I ≥ 3σ(F2). The central nickel is coordinated in a distorted square-planar fashion by four nitrogens. The pair of the planar dipyrrinato ligands enclose a dihedral angle of 38.5°. This is the lowest angle reported for nickel(II) complexes of this kind. As a result of this, and in sharp contrast to previously described nickel(II) dipyrrin chelates, the central metal is diamagnetic. Key words: meso-phenyldipyrromethanes, meso-phenyldipyrrins, meso-phenyldipyrrinato transition metal chelates, X-ray crystallography.

Cyano-bridged heterodinuclear complexes of nickel(II) and palladium(II). A disordered structure for the linkage isomer [LPd-CN-NiL](ClO4)

1992 ◽  
Vol 70 (9) ◽  
pp. 2461-2467 ◽  
Author(s):  
Parimal Paul ◽  
Ramprasad Das ◽  
Kamalaksha Nag ◽  
Eric J. Gabe ◽  
Jean-Pierre Charland
Keyword(s):  
Direct Methods ◽  
The Other ◽  
Tridentate Ligand ◽  
Full Matrix ◽  
X Ray ◽  
Disordered Structure ◽  
Metal Atoms ◽  
Square Planar ◽  
C And N ◽  
Cyanide Bridge

The homodinuclear [M2L2μ(CN)](ClO4) complexes and the heterodinuclear [LPd-CN-NiL](ClO4) and [LNi-CN-PdL](ClO4) complexes of nickel(II) and palladium(II) have been synthesized with a tridentate ligand HL (methyl 2-[(2′-aminoethyl)amino]cyclopent-1-enedithiocarboxylate). In solution both the isomers dissociate, [LNi-CN-PdL]+ much more rapidly than [LPd-CN-NiL]+, and a steady state equilibrium between the [LPd-CN-NiL]+, [Pd2L2μ-(CN)]+, and [Ni2L2μ-(CN)]+ species is established. The isomer [LPd-CN-NiL]+ exhibits a band at 555 nm that is absent in the other isomer and homodinuclear complexes. The X-ray structure of [LPd-CN-NiL](ClO4) has been studied. Crystals of the compound are monoclinic, a = 8.964(2), b = 23.852(2), c = 14.096(2) Å, β = 105.92(1)°, Z = 4, space group P21/a. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.054 and Rw = 0.034 for 4426 reflections with I ≥ 2.5σ(I). The two metal centres are in a square-planar environment provided by the N2S donor set of the ligand and cyanide bridge, but the metal atoms as well as C and N atoms of μ-CN could not be distinguished due to disorder. An alternate stacking of Pd-CN-Ni and Ni-NC-Pd units has been proposed to explain the 1:1 occupancy of the atoms concerned.

scholarly journals Pd(II) and Zn(II) Complexes with 9-Anthraldehyde 3-tetramethyleneiminylthiosemicarbazone

2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Dinh Thi Hien ◽  
Khuat Thi Thuy Ha ◽  
Nguyen Minh Hai
Keyword(s):  
Metal Ions ◽  
Central Metal ◽  
X Ray ◽  
X Ray Crystallography ◽  
Square Planar ◽  
Mononuclear Structure

Two Pd(II) and Zn(II) complexes with an anthracene-based thiosemicarbazone (H-5cATSC) have been conveniently prepared. Reaction of the ligand with relevant metal precusors yields the complexes Pd-5cATSC and Zn-5cATSC which have been then structurally determined by X-ray crystallography. The results reveals that the complexes are of mononuclear structure and adopts square-planar and tetrahedral geometries around the central metal ions.

Reactions of lignin model compounds with pulp bleaching chemicals. Cannizzaro-type reaction of tetrachloro-o-benzoquinone with alkali

1992 ◽  
Vol 70 (6) ◽  
pp. 1706-1710 ◽  
Author(s):  
A. Bruce McKague ◽  
Douglas W. Reeve ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Direct Methods ◽  
Aqueous Sodium Hydroxide ◽  
Pulp Bleaching ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Full Matrix ◽  
Aqueous Sodium ◽  
X Ray ◽  
X Ray Crystallography ◽  
Lignin Model

Reaction of tetrachloro-o-benzoquinone 1 with aqueous sodium hydroxide resulted in a Cannizzaro-type disproportionation into tetrachloromuconic acid and tetrachlorocatechol. The tetrachloromuconic acid was isolated and identified by X-ray crystallography as the methyl ester of the cyclized lactone 3. Crystals of C7H3Cl3O4, 4, are orthorhombic, a = 9.991 (2), b = 7.981 (1), c = 24.626(2) Å, Z = 8, space group Pna21. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.033 for 1609 reflections with I ≥ 3σ(I).

The reaction of tetrasulphur dinitride with norbornadiene; the crystal and molecular structure of S4N2•C7H8, an eight-membered C2S4N2 heterocycle

1983 ◽  
Vol 61 (6) ◽  
pp. 1185-1188 ◽  
Author(s):  
Hans Koenig ◽  
Richard T. Oakley ◽  
A. Wallace Cordes ◽  
Mark C. Noble
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Dihedral Angle ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Crystallographic Analysis ◽  
Monoclinic Space Group ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

The reaction of tetrasulphur dinitride with norbornadiene produces the 1:1 adduct S4N2•C7H8; X-ray crystallographic analysis of this compound reveals that olefin addition cleaves one of the sulphur–sulphur bonds of S4N2, yielding a novel eight-membered C2S4N2 ring. Crystals of S4N2•C7H8 are monoclinic, space group P21/c, a = 6.127(1), b = 17.369(1), c = 9.580(1) Å, β = 106.74(1)°, V = 1003.8(5) Å3Z = 4. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.039. The S—S—N—S—N—S fragment of the C2S4N2 ring is planar to within 0.15 Å. The S—C—C—S unit is folded out of this plane to produce a dihedral angle of 74.5°.

scholarly journals Crystal Structure of Poly[(acetone-O)-3-((3,4-dimethoxyphenyl)(4-hydroxy-2-oxo-2H-chromen-3-yl)methyl)-(2-oxo-2H-chromen-4-olate)sodium]

2010 ◽  
Vol 2010 ◽  
pp. 1-7
Author(s):  
Anita Penkova ◽  
Pascal Retailleau ◽  
Ilia Manolov
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Direct Methods ◽  
Orthorhombic System ◽  
Full Matrix ◽  
X Ray ◽  
X Ray Crystallography

The structure of Poly[(acetone-O)-3-((3,4-dimethoxyphenyl)(4-hydroxy-2-oxo-2H-chromen-3-yl)methyl)-(2-oxo-2H-chromen-4-olate)sodium] was determined by X-ray crystallography. The compound crystallizes in an orthorhombic system and was characterized thus P 21 21 21, a=9.967(2) Å, b=11.473(3) Å, c=22.176(5) Å. Z=4, V=2535.9(10) Å3. The crystal structure was solved by direct methods and refined by full-matrix least-squares on F2 to final values of R1=0.0601 and wR2=0.1515.

The cycloaddition of norbornadiene to (triphenylphosphoranediyl)aminocyclotrithiatriazene; the crystal and molecular structure of Ph3PN—S3N3•C7H8

1983 ◽  
Vol 61 (9) ◽  
pp. 2062-2067 ◽  
Author(s):  
Stephen W. Liblong ◽  
Richard T. Oakley ◽  
A. Wallace Cordes ◽  
Mark C. Noble
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Monoclinic Space Group ◽  
Frontier Orbitals ◽  
Full Matrix ◽  
X Ray ◽  
X Ray Crystallography ◽  
Kinetics Of

The reaction of norbornadiene with (triphenylphosphoranediyl)aminocyclotrithiatriazene produces the cycloadduct Ph3PN—S3N3•C7H8. The crystal and molecular structure of this compound has been determined by X-ray crystallography. Crystals of Ph3PN—S3N3•C7H8 are monoclinic, space group P21/c, a = 9.757(1), b = 15.114(1), c = 16.535(2) Å, β = 100.73(1)°, V = 2395.7(9) Å3, and Z = 4. The structure was solved by direct methods and refined by Fourier and full-matrix least-squares procedures to give a final R of 0.040 and Rw of 0.058 for 2620 observed reflections. The structure reveals that the S3N3 ring adds to norbornadiene in an exo fashion via two sulphur atoms. The S3N3 ring adopts a chair conformation with the three ligands occupying axial positions on the same side of the ring. The relative rates of this and other cycloadditions involving SN substrates and olefins are discussed in terms of the energies of the interacting frontier orbitals. The results suggest that HOMO(olefin)–LUMO(SN substrate) interactions control the kinetics of these reactions.

Synthesis and characterization of [Me2Ga(3,5-Me2pz)2]Rh(CO)PPh3 and the X-ray structure of its toluene solvate

1985 ◽  
Vol 63 (2) ◽  
pp. 503-508 ◽  
Author(s):  
Brenda M. Louie ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Physical Properties ◽  
Least Squares ◽  
Heavy Atom ◽  
Synthesis And Characterization ◽  
Boat Conformation ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Square Planar

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.

scholarly journals Structural Characterization of Heterodinuclear ZnII-LnIII Complexes (Ln = Pr, Nd) with a Ring-Contracted H2valdien-Derived Schiff Base Ligand

2021 ◽  
Author(s):  
Shabana Noor ◽  
Richard Goddard ◽  
Fehmeeda Khatoon ◽  
Sarvendra Kumar ◽  
Rüdiger W. Seidel
Keyword(s):  
Molecular Structure ◽  
Schiff Base ◽  
Structural Characterization ◽  
Schiff Base Ligand ◽  
Crystal And Molecular Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
Imidazoline Ring

AbstractSynthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes with the formula [ZnLn(HL)(µ-OAc)(NO3)2(H2O)x(MeOH)1-x]NO3 · n H2O · n MeOH [Ln = Pr (1), Nd (2)] and the crystal and molecular structure of [ZnNd(HL)(µ-OAc)(NO3)2(H2O)] [ZnNd(HL)(OAc)(NO3)2(H2O)](NO3)2 · n H2O · n MeOH (3) are reported. The asymmetrical compartmental ligand (E)-2-(1-(2-((2-hydroxy-3-methoxybenzylidene)amino)-ethyl)imidazolidin-2-yl)-6-methoxyphenol (H2L) is formed from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation, resulting in a peripheral imidazoline ring. The structures of 1–3 were revealed by X-ray crystallography. The smaller ZnII ion occupies the inner N2O2 compartment of the ligand, whereas the larger and more oxophilic LnIII ions are found in the outer O2O2’ site. Graphic Abstract Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes (Ln = Pr, Nd) bearing an asymmetrical compartmental ligand formed in situ from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation are reported.

scholarly journals Characterization of Aptamer-Protein Complexes by X-ray Crystallography and Alternative Approaches

2012 ◽  
Vol 13 (8) ◽  
pp. 10537-10552 ◽  
Author(s):  
Vincent J. B. Ruigrok ◽  
Mark Levisson ◽  
Johan Hekelaar ◽  
Hauke Smidt ◽  
Bauke W. Dijkstra ◽  
...  
Keyword(s):  
Protein Complexes ◽  
X Ray ◽  
X Ray Crystallography ◽  
Alternative Approaches

Configurational and conformational studies on condensation products of biogenic amines with 2,5-anhydro-D-mannose

1985 ◽  
Vol 63 (11) ◽  
pp. 2915-2921 ◽  
Author(s):  
Ian M. Piper ◽  
David B. MacLean ◽  
Romolo Faggiani ◽  
Colin J. L. Lock ◽  
Walter A. Szarek
Keyword(s):  
Hydrogen Bond ◽  
Intermolecular Hydrogen Bond ◽  
Direct Methods ◽  
Conformational Studies ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Twist Conformation ◽  
Cell Dimensions ◽  
Internal Hydrogen Bond

The products of a Pictet–Spengler condensation of tryptamine and of histamine with 2,5-anhydro-D-mannose have been studied by X-ray crystallography to establish their absolute configuration. 1(S)-(α-D-Arabinofuranosyl)-1,2,3,4-tetrahydro-β-carboline (1), C16H20N20O4, is monoclinic, P21 (No. 4), with cell dimensions a = 13.091(4), b = 5.365(1), c = 11.323(3) Å, β = 115.78(2)°, and Z = 2. 4-(α-D-Arabinofuranosyl)imidazo[4,5-c]-4,5,6,7-tetrahydropyridine (3), C11H17N3O4, is orthorhombic, P212121 (No. 19), with cell dimensions a = 8.118(2), b = 13.715(4), c = 10.963(3) Å, and Z = 4. The structures were determined by direct methods and refined to R1 = 0.0514, R2 = 0.0642 for 3210 reflections in the case of 1, and to R1 = 0.0312, R2 = 0.0335 for 1569 reflections in the case of 3. Bond lengths and angles within both molecules are normal and agree well with those observed in related structures. In 3 the base and sugar adopt a syn arrangement, which is maintained by an internal hydrogen bond between O(2′) and N(3). The sugar adopts a normal 2T3 twist conformation. The sugar has the opposite anti arrangement in the β-carboline 1 and the conformation of the sugar is unusual; it is close to an envelope conformation with O(4′) being the atom out of the plane. This conformation is caused by a strong intermolecular hydrogen bond from O(5′) in a symmetry-related molecule to O(4′). Both compounds are held together in the crystal by extensive hydrogen-bonding networks. The conformations of the compounds in solution have been investigated by 1H nmr spectroscopy, and the results obtained were compared with those obtained by X-ray crystallography for 1 and 3.

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