40 research outputs found

    Synthesis, crystal and molecular structure of manganese (II) complex of 2-acetylpyridine N (4) ethylthiosemicarbazone

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    A novel Mn(II) complex with thiosemicarbazone derived from 2-acetylpyridine and N(4)-ethylthiosemicarbazide has been prepared. The single-crystal X-ray analysis of the Mn(II) complex showed a distorted octahedral MnN4S2 environment with the ligand chelating via the nitrogen and sulfur donor atoms in a tridentate manner. The triclinic form of the ligand which has crystallized in a monoclinic system in other works is also described. The basicity of  nitrogen atoms of the ligand was tested with its reaction with HNO3 and the structure of the salt obtained is reported. The result shows that the lone pair of the pyridine nitrogen is more available due to the delocalization of other nitrogen lone pair of electron. http://dx.doi.org/10.21060/cis.2016.41

    Structural studies of Schiff-base [2 + 2] macrocycles derived from 2,2′-oxydianiline and the ROP capability of their organoaluminium complexes

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    The molecular structures of a number of solvates of the [2 + 2] Schiff-base macrocycles {[2-(OH)-5-(R)-C6H2-1,3-(CH)2][O(2-C6H4N)2]}2 (R = Me L1H2, tBu L2H2, Cl L3H2), formed by reacting 2,6-dicarboxy-4-R-phenol with 2,2′-oxydianiline (2-aminophenylether), (2-NH2C6H4)2O, have been determined. Reaction of LnH2 with two equivalents of AlR′3 (R′ = Me, Et) afforded dinuclear alkylaluminium complexes [(AlR′2)2L1–3] (R = R′ = Me (1), R = tBu, R′ = Me (2), R = Cl, R′ = Me (3), R = Me, R′ = Et (4), R = tBu, R′ = Et (5), R = Cl, R′ = Et (6)). For comparative studies, reactions of two equivalents of AlR′3 (R′ = Me, Et) with the macrocycle derived from 2,2′-ethylenedianiline and 2,6-dicarboxy-R-phenols (R = Me L4H2, tBu L5H2) were conducted; the complexes [(AlMe)(AlMe2)L5]·2¼MeCN (7·2¼MeCN) and [(AlEt2)2L4] (8) were isolated. Use of limited AlEt3 with L3H2 or L5H2 afforded mononuclear bis(macrocyclic) complexes [Al(L3)(L3H)]·4toluene (9·4toluene) and [Al(L5)(L5H)]·5MeCN (10·5MeCN), respectively. Use of four equivalents of AlR′3 led to transfer of alkyl groups and isolation of the complexes [(AlR′2)4L1′–3′] (R = L2′, R′ = Me (11); L3′, R′ = Me (12); L1′, R′ = Et (13); L2′, R′ = Et (14); L3′, R′ = Et (15)), where L1′–3′ is the macrocycle resulting from double alkyl transfer to imine, namely {[2-(O)-5-(R)C6H2-1-(CH)-3-C(R′)H][(O)(2-(N)-2′-C6H4N)2]}2. Molecular structures of complexes 7·2¼MeCN, 8, 9·4toluene, 10·5MeCN and 11·1¾toluene·1¼hexane are reported. These complexes act as catalysts for the ring opening polymerisation (ROP) of ε-caprolactone and rac-lactide; high conversions were achieved over 30 min at 80 °C for ε-caprolactone, and 110 °C over 12 h for rac-lactide

    Tetracarbonyl[ N

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    Oligomerization of α-olefins by the dimeric nickel bisamido complex [Ni{1-N(PMes 2 -N(μ-PMes 2 )C 6 H 4 -κ 3 N , N' , P ,-κ 1 P' }] 2 activated by methylalumoxane (MAO)

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    The reaction of Li2[1,2-{N(PMes2)}2C6H4], formed in situ from n-BuLi and the corresponding amines, with 1 equiv. of [NiBr2(DME)] gives [Ni{1-N(PMes2)-2-N(μ-PMes2)C6H4-κ3N,N′,P-κ1P′}]2 (1). After activation by methylalumoxane (MAO), 1 is a highly a

    Tetracarbonyl-2κ 4

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    3.3.2. Synthesis, crystal structure and biological activity of 1-(phthalazin-1(2H)-one)[(Pyridin-2-yl)ethylidene]hydrazone and its cobalt (III) complex

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    A new mononuclear complex of cobalt (III) (2) with 1-(phthalazin-1(2H)-one)[(Pyridin-2-yl) ethylidene] hydrazone ligand (1) has been synthesized and characterized by elemental analysis, IR and mass spectroscopic techniques. The crystal structures of the free ligand (1) and its complex (2) have been determined by single crystal X-ray diffraction technique. In complex 2 the hydrazone ligand chelates to the cobalt (III) ion through nitrogen atoms in a tridentate manner, giving an octahedral geometry where the cobalt (II) was oxidized to cobalt (III). The antifungal activity of ligand 1 and its complex 2 was studied against Aspergillus niger, Aspergillus flavus and Candida albicans. The results revealed modest activity of complex 2 against the tested organism with inhibition zones of 14, 15 and 14 mm, compared to the free ligand 1 with the inhibition zones of 12, 11 and 12 mm for A. niger, A. flavus, C. albicans respectively

    Synthesis, molecular and crystal structure of 1-(1,2-dihydrophthalazin-1-ylidene)-2-[1-(thiophen-2-yl)ethylidene]hydrazine

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    The title compound, C14H12N4S, was synthesized by the condensation reaction of hydralazine and 2-acetylthiophene and during the reaction, a proton transfer from the imino nitrogen atom to one of the endocylic nitrogen atoms occurred. The compound crystallizes in the monoclinic crystal system with two independent molecules (molecules 1 and 2) in the asymmetric unit. In each molecule, there is a slight difference in the orientation of the thiophene ring with respect to phthalazine ring system, molecule 1 showing a dihedral angle of 42.51 (1)° compared to 8.48 (1)° in molecule 2. This implies an r.m.s deviation of 0.428 (1) Å between the two molecules for the 19 non-H atoms. The two independent molecules are connected via two N—H...N hydrogen bonds, forming dimers which interact by two bifurcated π–π stacking interactions to build tetrameric motifs. The latter are packed in the ac plane via weak C—H...π interactions and along the b axis via C—H ...N and C—H...π interactions. This results a three-dimensional architecture with a tilted herringbone packing mode
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