Saeed Dehghanpour

Cobalt(II), nickel(II), and zinc(II) complexes with bidentate N,N′-bis(β-phenylcinnamaldehyde)-1,2-diiminoethane Schiff base: synthesis and structures

A series of complexes of the type M(Phca2en)X2, where Phca2en� /N ,N ?-bis(b-phenyl-cinnamaldehyde)-1,2-diiminoethane, M(II) � /Co, Ni or Zn and X � /Cl, Br, I or NCS have been synthesized and characterized. The crystal and molecular structures of Co(Phca2en)Cl2 (2), Ni(Phca2en)Br2 (5) and Zn(Phca2en)Cl2 (6) were determined by X-ray crystallography from single-crystal data. Complexes 2 and 5 are isomorph and isostructure, in which the coordination polyhedron about the central metal ion is distorted tetrahedron with Cl� /Co� /Cl, 110.17(6)8 ;N � /Co � /N, 84.16(13)8 and Cl� /Zn � /Cl, 112.02(6)8 ;N � /Zn� /N, 83.45(16)8. The complex 5 crystallizes in triclinic system with two molecules per asymmetric unit, both having nickel ion in distorted tetrahedral geometry, Br � / Ni � /Br, 122.645(18)8 and 125.729(18)8 ;N � /Ni � /N, 84.63(9)8 and 85.08(9)8. These structures consist of intermolecular hydrogen bonds of the type C � /H �� � X. The formation of the C � /H ��� M weak intramolecular hydrogen bonds due to the trapping of C� /H bonds in the vicinity of the metal atoms are reported for 2, 5 and 6 .A 1 H NMR study of Zn complexes gives further evidence for the presence of such interactions and their significance. The spectral properties of the above complexes are also discussed. # 2002 Elsevier Science Ltd. All rights reserved.

Facile electrosynthesis of nano flower like metal-organic framework and its nanocomposite with conjugated polymer as a novel and hybrid electrode material for highly capacitive pseudocapacitors

The [Cu(btec)0.5DMF] (H4btec=1,2,4,5-benzenetetracarboxylate acid) was electrosynthesized on the graphite working electrode by applying catholic potential. The [Cu(btec)0.5DMF] grows on a graphite surface which results from the coordination of 1,2,4,5-benzenetetracarboxylate anions with Cu2+ cations. The electrosynthesized [Cu(btec)0.5DMF] was characterized by X-ray diffraction, scanning electron microscopy. Furthermore, POAP/Cu(btec)0.5DMF nanocomposite film electrosynthesized on the surface of the carbon paste electrode by cyclic voltammetry. Different electrochemical methods including galvanostatic charge-discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy are carried out in order to investigate the performance of the system. This work introduces new nanocomposite materials for electrochemical redox capacitors with advantages including ease synthesis, high active surface area and stability in an aqueous electrolyte.

Synthesis, Characterization, and Crystal Structures of [Cu(ca2en)(PPh3)(X)] (X = Cl, Br, I, NCS, N3) Complexes

Novel mixed-ligand copper(I) complexes, [Cu(ca2en)(PPh3)X] (ca2en = N,N′-bis(trans-cinnamaldehyde)-1,2-diaminoethane, X = Cl (1), Br (2), I (3), NCS (4), N3 (5)), have been synthesized and characterized by 1H and 31P NMR spectroscopy, infrared spectroscopy, and elemental analyses. The single crystal X-ray structures of complexes (1)–(5) have been determined. All five complexes reveal discrete monomeric structures in the crystal. The geometry around the copper atom is in each case a distorted tetrahedron, with the distortion most pronounced in (3). The NCS− and N3− are coordinated as terminal ligands and the NCS− ligand is N-bonded in (4). Dynamic 31P NMR studies show partial bond breaking in solution.

Synthesis, Characterization, and Crystal Structures of [Cu(ca2en)2]ClO4, and [Cu(ca2en)(PPh3)2]ClO4 Complexes

Synthesis, spectroscopy, and crystal structures of [Cu(ca2en)2]ClO4 (1) and [Cu(ca2en)(PPh3)2]ClO4 (2) (ca2en=N,N′-bis(trans-cinnamaldehyde)ethylenediimine) are reported. Compound 1 crystallizes in the orthorhombic space group Pbca, with a=12.5647(7), b=21.8203(11), c=27.992(2) A, V=7674.3(7) A3, Z=8. Compound 2 crystallizes in the triclinic space group P, with a=13.0540(11), b=14.2935(13), c=14.9863(13) A, α=84.130(2), β=69.761(2), γ=87.749(2)°, V=2609.8(4) A3, Z=2. The coordination polyhedron about the CuI center in the two complexes is best described as a distorted tetrahedron. The 1H-NMR and electronic spectra of these complexes are also reported and discussed. The cyclic voltammetry of the complexes indicate a quasireversible redox behavior for complex 1 (E1/2=0.51 V). However, complex 2 displays an irreversible oxidation wave at 0.91 V. A weak emission is observed for complex 2 in CHCl3 at room temperature.

Solid state and solution study of some phosphoramidate derivatives containing the P(O)NHC(O) bifunctional group: Crystal structures of CCl2HC(O)NHP(O)(NCH3(CH2C6H5))2, p-ClC6H4C(O)NHP(O)(NCH3(CH2C6H5))2, CCl2HC(O)NHP(O)(N(CH2C6H5)2)2 and p-BrC6H4C(O)NHP(O)(N(CH2C6H5)2)2

Synthetic methods for several novel phosphoramidate compounds containing the P(O)NHC(O) bifunctional group were developed. These compounds with the general formula R(1)C(O)NHP(O)(N(R(2))(CH(2)C(6)H(5)))(2), where R(1)=CCl(2)H, p-ClC(6)H(4), p-BrC(6)H(4), o-FC(6)H(4) and R(2)=hydrogen, methyl, benzyl, were characterized by several spectroscopic methods and analytical techniques. The effects of phosphorus substituents on the rotation rate around the P-N(amine) bond were also investigated. (1)H NMR study of the synthesized compounds demonstrated that the presence of bulky groups attached to the phosphorus center and electron withdrawing groups in the amide moiety lead to large chemical-shift non-equivalence (Deltadelta(H)) of diastereotopic methylene protons. The crystal structures of CCl(2)HC(O)NHP(O)(NCH(3)(CH(2)C(6)H(5)))(2), p-ClC(6)H(4)C(O)NHP(O)(NCH(3)(CH(2)C(6)H(5)))(2), CCl(2)HC(O)NHP(O)(N(CH(2)C(6)H(5))(2))(2) and p-BrC(6)H(4)C(O)NHP(O)(N(CH(2)C(6)H(5))(2))(2) were determined by X-ray crystallography using single crystals. The coordination around the phosphorus center in these compounds is best described as distorted tetrahedral and the P(O) and C(O) groups are anti with respect to each other. In the compound Br-C(6)H(4)C(O)NHP(O)(N(CH(2)C(6)H(5))(2))(2) (with two independent molecules in the unit cell), two conformers are connected to each other via two different N-H...O hydrogen bonds forming a non-centrosymmetric dimer. In the crystalline lattice of other compounds, the molecules form centrosymmetric dimers via pairs of same N-H...O hydrogen bonds. The structure of CCl(2)HC(O)NHP(O)(N(CH(2)C(6)H(5))(2))(2) reveals an unusual intramolecular interaction between the oxygen of C=O group and amine nitrogen.

N,N'-Ethylene-bis(benzoylacetoniminato) Copper (II), Cu(C22H22N2O2), a New Reagent for Aromatization of Hantzsch 1,4-Dihydropyridines

A variety of Hantzsch 1,4-dihydropyridines were oxidized to their corresponding pyridines in high yields in the presence of Cu(C22H22N2O2) in refluxing acetic acid.

Three-Dimensional Metal–Organic Framework Graphene Nanocomposite as a Highly Efficient and Stable Electrocatalyst for the Oxygen Reduction Reaction in Acidic Media

We report on the design of a bio‐inspired composite as a noble‐metal‐free electrocatalyst for the oxygen reduction reaction (ORR). The composite is made from the assembly of pyridine‐functionalized graphene (G‐py) and a 3 D metal–organic framework (MOF) deposited onto a glassy carbon electrode (GCE). The 3 D heme‐like MOF was synthesized from tetrakis(4‐carboxyphenyl)porphyrin iron(III) chloride and Zr6 clusters for the assembly of the stable porous coordination network. G‐py, which possesses an axial ligand to anchor to the centers of porphyrin in the MOF, results in a significant change in the electronic and geometric structure of centers, which enhances the rate of ORR and durability during cycling in acidic media. The occurrence potential of the ORR by the composite is shifted to the positive potential near 100 mV. Our results introduce a new strategy for the rational design of inexpensive and highly stable oxygen reduction electrocatalysts for fuel cells without the requirement of pyrolysis.

Synthesis and Characterization of Cobalt(II), Nickel(II), and Zinc(II) Complexes with N,N′‐bis(2‐nitrocinnamaldehyde)‐1,2‐diiminoethane Ligand. Crystal Structure of Zn(nca2en)Br2

A series of complexes of the type M(nca2en)X2, where nca2en=/N,N′‐bis(2‐nitrocinnamaldehyde)‐1,2‐diiminoethane, M(II) =Co, Ni or Zn and X=Cl, Br, I have been synthesized and characterized. The crystal and molecular structure of Zn(nca2en)Br2 8 was determined by X‐ray crystallography from single‐crystal data. The complex 8 crystallizes in monoclinic system, having Zn ion in distorted tetrahedral geometry, Br(1)‐Zn(1)‐ Br(2), 117.37(4)°; N(3)‐Zn(1)‐N(2), 82.57(18)°. This structure consists of intermolecular hydrogen bond of the type C‐H‐X. The formation of the C‐H‐M weak intramolecular hydrogen bonds due to the trapping of C‐H bonds in the vicinity of the metal atoms is reported for 8. The 1H NMR study of Zn complexes gives further evidence for the presence of such interactions. The spectral properties of the above complexes are also discussed.

Synthesis and characterization of [Cu(mb2en)2]ClO4 and [Cu(mb2en)(PPh3)2]BPh4: crystal structure of [Cu(mb2en)2]ClO4

The ligand, N,N′-bis-(4-methoxy-benzylidene)-ethane-1,2-diamine (mb2en), and its corresponding copper(I) complexes, [Cu(mb2en)2]ClO4 (1), and [Cu(mb2en)(PPh3)2]BPh4 (2), have been synthesized and characterized by CHN analyses, 1H and 13C-NMR, IR, and UV-Vis spectroscopies. The crystal and molecular structure of [Cu(mb2en)2]ClO4 (1), were determined by X-ray crystallography from a single-crystal. The coordination polyhedron about copper(I) is best described as a distorted tetrahedron. Quasi-irreversible redox behavior was observed for 1 and 2 (E 1/2 = 0.55 and 0.95 V, respectively).

Di-μ-chlorido-bis-{chlorido[4-nitro-N-(pyridin-2-yl-methyl-idene-κN)aniline-κN]mercury(II)}.

In the centrosymmetric dinuclear title complex, [Hg2Cl4(C12H9N3O2)2], the HgII ion is in a distorted square-pyramidal coordination environment formed by the N atoms of the diimine ligand, two bridging Cl atoms and one terminal Cl atom. One of the bridging Hg—Cl bonds is significantly longer than the other.