79 research outputs found
The supramolecular arrangement in the Ni(II) complexes of isothiosemicarbazide
The molecules of two complexes [Ni(ITSC)2(H2O)2](tere)Ī2H2O and [Ni(ITSC)2(NO3)2] (ITSC = S-methylisothiosemicarbazide; tere = terephthalate) tend to associate trough the hydrogen bonding interactions into the characteristic 2D blocks separated by the S-methyl moieties. The different coordination mode of the isothiosemicarbazide comparing to thiosemicarbazide (TSC) prevents the formation of the complementary hydrogen bonds with dicarboxylate important for selfassambly of TSC complexes, however in these ITSC the terephthalate anion has role in connection of the blocks and transformation of the 2D into the 3D supramolecular structure. The similar crystal arrangement is found in two earlier reported complexes of Ni(II) with ITSC.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200
Comparison of two views regarding the nature of the X-Hā¦phenyl interaction
There are two approaches in the analysis of the nature of the X-Hā¦phenyl interactions. One is based on the assumption that atoms, bonds and the Ļ plane belonging to the phenyl ring, are the points which can be involved in the interaction. The other states that center of the phenyl ring is the point acceptor. In this paper we compare two views using the directionality of the X-H vector and length/angle correlations relative to both assumed point acceptors. The results suggest that on the basis of this methodology there is no clear answer regarding the nature of the acceptor site in the phenyl ring.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200
Transition metal complexes with Girard reagents and their hydrazones
This is the first review dealing with the coordination chemistry of metal complexes with Girard's reagents and their hydrazones. The short introduction points out to chemical properties and significance of these organic compounds. The next section briefly describes synthetic methods for preparing complexes with Girard's reagents, as well as modes of coordination of these ligands. The last two extensive sections review the preparation, stereochemistry and structural characteristics of metal complexes with Girard's hydrazones, including some newer non-hydrazonic derivatives of Girard's reagents, also.[Acknowledgments. Projekat Ministarstva nauke Republike Srbije, br. 172014
Crystal structure of 4-bromo-2-(1H-pyrazol-3-yl)phenol, C9H7BrN2O (vol 232, pg 507, 2017)
C9H7BrN2O, monoclinic, C2/c (no. 15), a = 16.255(3) angstrom, b = 4.4119(9) angstrom, c = 25.923(5) angstrom, beta = 107.99(3)degrees, V = 1768.2(7) angstrom(3), Z = 8, R-gt(F) = 0.0450, wR(ref)(F-2) = 0.0960, T = 150 K
Elektrohemijsko generisanje katalizatora za Majklovu adiciju dikarbonilnih jedinjenja i cijanida na akriloilferocen
Michael addition of diethyl malonate, ethyl acetoacetate, acetylacetone, and cyanide anion to acryloylferrocene promoted by a catalyst in situ generated from a sacrificial zirconium anode is described. Most of the obtained compounds were identified by comparison of their spectral and physical data with those published elsewhere, whereas the only newly synthesized compound - diethyl 2,2-bis(3-ferrocenyl-3-oxopropyl)malonate - was completely characterized by spectral (IR, 1H- and 13C-NMR), physical and crystallographic (single-crystal X-ray) data.Opisana je Majklova adicija dietil-malonata, etil-acetoacetata, acetilacetona i cijanidnog anjona na akriloilferocen pomoÄu katalizatora generisanog in situ sa rastvorne anode od cirkonijuma. VeÄina dobijenih jedinjenja je identifikovana poreÄenjem njihovih fiziÄkih i spektroskopskih podataka sa literaturnim, a jedino novo jedinjenje je potpuno opisano spektroskopskim (IR, 1H- i 13C-NMR) i fiziÄkim podacima, kao i podacima iz kristalografske analize X-zracima
Synthesis, crystal structure and biological activity of copper(II) complex with 4-nitro-3-pyrazolecarboxylic ligand
The reaction of 4-nitro-3-pyrazolecarboxylic acid and Cu(OAc)2ā
H2O in ethanol resulted in a new coordination compound [Cu2(4-nitro-3- -pzc)2(H2O)6]2H2O (4nitro-3pzc = 4-nitro-3-pyrazolecarboxylate). The compound was investigated by means of single-crystal X-ray diffraction and infrared spectroscopy. The biological activity of the complex was also tested. In the crystal structure of [Cu2(4nitro-3-pzc)2(H2O)6]2H2O, the Cu(II) ion is in a distorted [4+2] octahedral coordination due to the JanāTeller effect. A survey of the Cambridge Structural Database showed that the octahedral coordination geometry is generally rare for pyrazole-bridged Cu(II) complexes. In the case of Cu(II) complexes with the 3-pyrazolecarboxylato ligands, no complexes with a similar octahedral coordination geometry have been reported. Biological research based on determination of the inhibition effect of the commercial fungicide Cabrio top and the newly synthesized complex on Ph. viticola were performed using the phytosanitary method
Crystal structure of tetraaqua[2-(pyridin-2-yl)-1H-imidazole-kappa N-2(2),N-3]iron(II) sulfate
In the title compound, [Fe(C8H7N3)(H2O)(4)]SO4, the central Fe-II ion is octahedrally coordinated by two N atoms from the bidentate 2-(pyridin-2-yl)-1H-imidazole ligand and by four O atoms of the aqua ligands. The largest deviation from the ideal octahedral geometry is reflected by the small N-Fe-N bite angle of 76.0 (1)degrees. The Fe-N coordination bonds have markedly different lengths [2.1361 (17) and 2.243 (2) angstrom], with the shorter one to the pyrimidine N atom. The four Fe-O coordination bond lengths vary from 2.1191 (18) to 2.1340 (17) angstrom. In the crystal, the cations and anions are arranged by means of medium-strength O-H center dot center dot center dot O hydrogen bonds into layers parallel to the ab plane. Neighbouring layers further interconnect by N-H center dot center dot center dot O hydrogen bonds involving the imidazole fragment as donor group to one sulfate O atom as an acceptor. The resulting three-dimensional network is consolidated by C-H center dot center dot center dot O, C-H center dot center dot center dot pi and pi-pi interactions
Synthesis and structural characterization of Cd(II) complexes with 2-acetylpyridine-aminoguanidine - a novel coordination mode
The structures of the first two complexes with bidentate coordination of aminoguanidine Schiff base, i.e., 2-acetylpyridine-aminoguanidine (L), are reported. The complex of the formula [Cd2Cl6(HL)2] (1) was obtained in the reaction of warm aqueous solutions of chloride salts of Cd(II), Zn(II) and the ligand, while the reaction of cadmium bromide and the ligand in the presence of deprotonating agent as well as ammonium thiocyanate resulted in the formation of the complex in which Schiff base has both the role of the ligand and the counterion, viz., [HL][Cd(HL)(NCS)2XY]Ā·H2O (2), where X is Cl- or Br-, and Y Br- or SCN-. The complexes were characterized by IR spectroscopy, elemental analysis, conductometric measurements and single crystal X-ray diffraction. The unusual bidentate coordination of the Schiff base lead to significant changes in the geometry of this molecule (from almost planar in free form and as a tridentate ligand to twisted as a bidentate ligand). Besides, in complex 1 relatively rare bridging coordination of Cl- in octahedral Cd(II) is found, while the crystal structure of complex 2 exhibits substitutional disorder, and contains four different anions: [Cd(HL)(NCS)2Br(SCN)]- (ca. 61 %), [Cd(HL)(NCS)2Cl(SCN)]- (ca. 35 %), [Cd(HL)(NCS)2Br2]- (ca. 3 %) and [Cd(HL)(NCS)2ClBr]- (ca. 1 %)
Crystal structure of ethyl 3-(trifluoromethyl)-1H-pyrazole-4-carboxylate, C7H7F3N2O2
C7H7F3N2O2, monoclinic, P21/m (no. 11), a = 6.8088(8) Ć
, b = 6.7699(9) Ć
, c = 9.9351(12) Ć
, Ī² = 105.416(3)Ā°, V = 441.48(9) Ć
3 , Z = 2, R gt ( F ) = 0.0398, wR ref ( F 2 ) = 0.1192, T = 200(2) K
Crystal structure of dihydrazinium 1H-pyrazole-3,5-dicarboxylate, C5H12N6O4
C 5 H 12 N 6 O 4 , monoclinic, P 2 1 / n (no. 14), a = 4.3368(6) Ć
, b = 15.483(2) Ć
, c = 13.8852(19) Ć
, Ī² = 97.714(3)Ā°, V = 923.9(2) Ć
3 , Z = 4, R gt ( F ) = 0.0411, wR ref ( F 2 ) = 0.1109, T = 200(2) K
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