scholarly journals Structure of tetrakis(μ-decanoato-κ2 O:O′)bis[(4-methylpyridine-κN)copper(II)], a dimeric copper(II) complex

2020 ◽  
Vol 76 (11) ◽  
pp. 1775-1778
Author(s):  
Monsumi Gogoi ◽  
Birinchi Kumar Das
Keyword(s):  
Coordination Mode ◽  
Carboxylate Ligands ◽  
Paddle Wheel ◽  
Carboxylate Complex ◽  
Dinuclear Cluster

The 4-methylpyridine (4-Mepy) based dimeric copper(II) carboxylate complex [Cu2(C10H19O2)4(C6H7N)2] or [Cu2(μ-O2CC9H19)4(4-Mepy)2] crystallizes with triclinic (P\overline{1}) symmetry. The two CuII ions exhibit a distorted square-pyramidal environment and are connected into a centrosymmetric paddle-wheel dinuclear cluster [Cu...Cu = 2.6472 (8) Å] via four bridging carboxylate ligands arranged in the syn–syn coordination mode. The apical positions around the paddle-wheel copper centers are occupied by the N atoms of the 4-methylpyridine ligands. The structure exhibits disorder of the terminal alkyl carbon atoms in the decanoate chains.

scholarly journals The first coordination compound of deprotonated 2-bromonicotinic acid: crystal structure of a dinuclear paddle-wheel copper(II) complex

2020 ◽  
Vol 76 (2) ◽  
pp. 225-230
Author(s):  
Nives Politeo ◽  
Mateja Pisačić ◽  
Marijana Đaković ◽  
Vesna Sokol ◽  
Boris-Marko Kukovec
Keyword(s):  
Crystal Structure ◽  
Coordination Mode ◽  
Hirshfeld Surface ◽  
Two Dimensional ◽  
Apical Position ◽  
Coordination Environment ◽  
Paddle Wheel ◽  
Chloride Dihydrate ◽  
Intermolecular Contacts ◽  
Dinuclear Cluster

A copper(II) dimer with the deprotonated anion of 2-bromonicotinic acid (2-BrnicH), namely, tetrakis(μ-2-bromonicotinato-κ2 O:O′)bis[aquacopper(II)](Cu—Cu), [Cu2(H2O)2(C6H3BrNO2)4] or [Cu2(H2O)2(2-Brnic)4], (1), was prepared by the reaction of copper(II) chloride dihydrate and 2-bromonicotinic acid in water. The copper(II) ion in 1 has a distorted square-pyramidal coordination environment, achieved by four carboxylate O atoms in the basal plane and the water molecule in the apical position. The pair of symmetry-related copper(II) ions are connected into a centrosymmetric paddle-wheel dinuclear cluster [Cu...Cu = 2.6470 (11) Å] via four O,O′-bridging 2-bromonicotinate ligands in the syn-syn coordination mode. In the extended structure of 1, the cluster molecules are assembled into an infinite two-dimensional hydrogen-bonded network lying parallel to the (001) plane via strong O—H...O and O—H...N hydrogen bonds, leading to the formation of various hydrogen-bond ring motifs: dimeric R 2 2(8) and R 2 2(16) loops and a tetrameric R 4 4(16) loop. The Hirshfeld surface analysis was also performed in order to better illustrate the nature and abundance of the intermolecular contacts in the structure of 1.

A novel coordination mode for dithiatetrazocines: preparation, x-ray structure, and fluxional behavior of [Pt(PPh3)(1,5-Ph4P2N4S2)]2

1990 ◽  
Vol 29 (17) ◽  
pp. 3068-3069 ◽  
Author(s):  
Tristram Chivers ◽  
Mark Edwards ◽  
Pramesh N. Kapoor ◽  
Auke Meetsma ◽  
Johan C. Van de Grampel ◽  
...  
Keyword(s):  
Coordination Mode ◽  
X Ray

scholarly journals The Role of the Disulfide Bridge in the Copper (II) Binding by the Cyclic His4-Peptide

2021 ◽  
Vol 22 (12) ◽  
pp. 6458
Author(s):  
Aleksandra Pieniężna ◽  
Weronika Witak ◽  
Aneta Szymańska ◽  
Justyna Brasuń
Keyword(s):  
Metal Ions ◽  
Coordination Mode ◽  
Transition Metal Ions ◽  
Disulfide Bridge ◽  
Chain Flexibility ◽  
Vis Spectroscopy ◽  
Ph Range ◽  
Cd Studies ◽  
Metal Ratios

In this paper, we present studies on the influence of the disulfide bridge on the copper (II) ions’ binding abilities by the cyclic His4-peptide. The studied ligand HKHPHRHC-S-S-C consists of nine amino acids. The cyclic structure was obtained through a disulfide bridge between two cysteinyl groups. Moreover, this peptide is characterized by the presence of four His residues in the sequence, which makes it an interesting ligand for transition metal ions. The potentiometric and spectroscopic (UV-Vis spectroscopy and circular dichroism spectroscopy (CD)) studies were carried out in various molar ligand to metal ratios: 2:1, 1:1, and 1:2, in the pH range of 2.5–11 at 25 °C. The results showed that the cyclic His4-peptide promotes dinuclear complexes in each of these systems and forms the final dinuclear species with the {NIm, 3N-amide}{NIm, 3N-amide} coordination mode. The obtained data shows that cyclization by the formation of the disulfide bond has an impact on the peptide chain flexibility and appearance of additional potential donors for metal ions and influences the copper (II) ions’ coordination.

A 4-acyl-5-pyrazolone ligand (HQ) in N-unidentate coordination mode in a Rh(CO)2Cl(HQ)-type complex

2004 ◽  
Vol 7 (2) ◽  
pp. 235-237 ◽  
Author(s):  
Augusto Cingolani ◽  
Fabio Marchetti ◽  
Claudio Pettinari ◽  
Riccardo Pettinari ◽  
Brian W. Skelton ◽  
...  
Keyword(s):  
Coordination Mode ◽  
Type Complex

scholarly journals Iron(II) complexes of dimethyltriazacyclophane

2018 ◽  
Vol 74 (12) ◽  
pp. 1641-1649
Author(s):  
Wei-Tsung Lee ◽  
Matthias Zeller ◽  
David Upp ◽  
Yuliya Politanska ◽  
Doug Steinman ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Dft Calculations ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Coordination Mode ◽  
Functional Theory ◽  
Metal Centers ◽  
Bonding Interaction

Treatment of the ortho-triazacyclophane 1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-triene [(C6H5)3(NH)(NCH3)2, L1] with Fe[N(SiMe3)2]2 yields the dimeric iron(II) complex bis(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido)bis[(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido)iron(II)], [Fe(C20H18N3)4] or Fe2(L1)4 (9). Dissolution of 9 in tetrahydrofuran (THF) results in solvation by two THF ligands and the formation of a simpler monoiron complex, namely bis(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido-κN 7)bis(tetrahydrofuran-κO)iron(II), [Fe(C20H18N3)2(C4H8O)2] or (L1)2Fe(THF)2 (10). The reaction is reversible and 10 reverts in vacuo to diiron complex 9. In the structures of both 9 and 10, the monoanionic triazacyclophane ligand L1− is observed in only the less-symmetric saddle conformation. No bowl-shaped crown conformers are observed in the solid state, thus preventing chelating κ3-coordination to the metal as had been proposed earlier based on density functional theory (DFT) calculations. Instead, the L1− ligands are bound in either a η2-chelating fashion through the amide and one amine donor (for one of the four ligands of 9), or solely through their amide N atoms in an even simpler monodentate η1-coordination mode. Density functional calculations on dimer 9 revealed nearly full cationic charges on each Fe atom and no bonding interaction between the two metal centers, consistent with the relatively long Fe...Fe distance of 2.912 (1) Å observed in the solid state.

Synthesis, structure, and magnetic properties of two dimer paddle-wheel CuII toluate complexes with nitronyl nitroxide radicals

2013 ◽  
Vol 66 (12) ◽  
pp. 2166-2177 ◽  
Author(s):  
Jie Zhou ◽  
Lin Du ◽  
Zongze Li ◽  
Yongfeng Qiao ◽  
Jing Liu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Nitronyl Nitroxide ◽  
Nitroxide Radicals ◽  
Paddle Wheel
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