Synthesis of a Square-Planar Rhodium Alkylidene N-Heterocyclic Carbene Complex and Its Reactivity Toward Alkenes

Abstract The reaction of the dibenzotetraazafulvalene C6H4(NC2H5)2C=C(NC2H5)2C6H4, 1 = 1, with [(COD)Rh(μ-Cl)2Rh(COD)] proceeds via cleavage of the C=C double bond and yields the carbene complex [(COD)RhCl(1)], 2. The X-ray structure analysis shows 2 to be a mononuclear complex with a rhodium(I) center coordinated in a slightly distorted square-planar fashion.

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High Magnetic Anisotropy of a Square-Planar Iron-Carbene Complex

Inorganic Chemistry ◽

10.1021/acs.inorgchem.1c01860 ◽

2021 ◽

Author(s):

Brett M. Hakey ◽

Dylan C. Leary ◽

Jin Xiong ◽

Caleb F. Harris ◽

Jonathan M. Darmon ◽

...

Keyword(s):

Magnetic Anisotropy ◽

Carbene Complex ◽

Square Planar

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Dimerization of a mixed-carbene PdII dibromide complex by elemental iodine

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229617016412 ◽

2017 ◽

Vol 73 (12) ◽

pp. 1131-1136 ◽

Cited By ~ 1

Author(s):

Christian Jandl ◽

Alexander Pöthig

Keyword(s):

Single Crystal ◽

Bulk Material ◽

Dimeric Complex ◽

Carbene Complex ◽

Counter Ions ◽

Square Planar ◽

Complex Features ◽

Elemental Iodine

A monomeric PdII complex bearing a mixed carbocyclic/N-heterocyclic carbene ligand and two bromides was reacted with an excess of elemental iodine, which resulted in the surprising removal of one bromide ligand and dimerization of the mixed-carbene complex to form di-μ-bromido-bis{[1-(cyclohepta-2,4,6-trien-2-yl-1-ylidene-κC 1)-3-(2,6-diisopropylphenyl)imidazol-2-ylidene]palladium(II)} bis(pentaiodide) dichloromethane monosolvate, [Pd2Br2(C22H24N2)2](I5)2·CH2Cl2. The dimeric complex features a slightly distorted square-planar core of two PdII centres bridged by two bromide ligands, which lie in the same plane as the seven- and five-membered rings of the bidentate carbene ligand. The counter-ions in the single crystal were found to be pentaiodide monoanions featuring their typical V-shape, whereas for the bulk material, a mixture of Br/I interhalides is proposed.

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Crystal structure of the [(1,3-dimesityl-1H-imidazol-3-ium-2-yl)methanolato]copper(II) chloride dimer: insertion of formaldehyde into a copper–carbene bond

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s205698901801201x ◽

2018 ◽

Vol 74 (9) ◽

pp. 1369-1372 ◽

Cited By ~ 1

Author(s):

Christopher A. Dodds ◽

Alan R. Kennedy

Keyword(s):

Crystal Structure ◽

Central Core ◽

Carbon Bond ◽

Carbene Complex ◽

Bond Lengths ◽

Binuclear Molecule ◽

Square Planar ◽

Chloride Ligands ◽

Planar Environment

The crystal structure of bis[μ-(1,3-dimesityl-1H-imidazol-3-ium-2-yl)methanolato-κ2 O:O]bis[dichloridocopper(II)], [Cu2Cl4(C22H26N2O)2], is reported. The complex is assumed to have formed via the insertion of formaldehyde into the copper–carbon bond in an N-heterocyclic carbene complex of copper(I) chloride. The structure of the binuclear molecule possesses a crystallographically centrosymmetric Cu2O2 central core with the O atoms bridging between the CuII atoms and thus Z′ = 0.5. The copper centres are further ligated by two chloride ligands, resulting in the CuII atoms residing in a distorted square-planar environment. The Cu—O bond lengths are shorter than those previously reported in structures with the same central Cu2O2 motif. The complex displays C—H...Cl interactions involving the H atoms of the heterocycle backbone and the chloride ligands of a neighbouring molecule.

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Crystal chemistry of high-Tc superconductors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100178720 ◽

1990 ◽

Vol 48 (4) ◽

pp. 1118-1119

Author(s):

Maryvonne Hervieu

Keyword(s):

Oxygen Deficiency ◽

Large Family ◽

Copper Oxides ◽

High Tc Superconductors ◽

High Tc ◽

Single Mechanism ◽

Square Planar ◽

History Of ◽

Bismuth Cuprates ◽

New Compounds

Four years after the discovery of superconductivity at high temperature in the Ba-La-Cu-O system, more than thirty new compounds have been synthesized, which can be classified in six series of copper oxides: La2CuO4 - type oxides, bismuth cuprates, YBa2Cu3O7 family, thallium cuprates, lead cuprates and Nd2CuO4 - type oxides. Despite their quite different specific natures, close relationships allow their structures to be simply described through a single mechanism. The fifth first families can indeed be described as intergrowths of multiple oxygen deficient perovskite slabs with multiple rock salt-type slabs, according to the representation [ACuO3-x]m [AO]n.The n and m values are integer in the parent structures, n varying from 0 to 3 and m from 1 to 4; every member of this large family can thus be symbolized by [m,n]. The oxygen deficient character of the perovskite slabs involves the existence or the co-existence of several types of copper environment: octahedral, pyramidal and square planar.Both mechanisms, oxygen deficiency and intergrowth, are well known to give rise easily to nonstoichiometry phenomena. Numerous and various phenomena have actually been characterized in these cuprates, strongly depending on the thermal history of the samples.

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On the Reactivity of mRNA Caps: C-H Oxidative Addition of 7-Methylguanosine to Pt(0)

10.26434/chemrxiv.8144297.v1 ◽

2019 ◽

Author(s):

Maria Ines Leitao ◽

Carmen Gonzalez ◽

Zuzanna Filipiak ◽

Ana Petronilho

Keyword(s):

Oxidative Addition ◽

Carbene Complex ◽

Proton Loss

<p>7-methylguanosine, the so-called mRNA cap 0 bears a very labile C8-H bond, due to the formation of an ylide/N-heterocyclic carbene, upon proton loss. The reaction of 7-methylguanosine with Pt(PPh3)4, via C-H oxidative addition, yields a hydrido–PtII carbene complex and this reactivity can be extrapolated to 7,9-dimethylguanine. </p>

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New Platinum (II) Ternary Complexes of Formamidine and Pyrophosphate: Synthesis, Characterization and DFT Calculations and In vitro Cytotoxicity

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207323666200218115700 ◽

2020 ◽

Vol 23 (7) ◽

pp. 611-623

Author(s):

Ahmed A. Soliman ◽

Fawzy A. Attaby ◽

Othman I. Alajrawy ◽

Azza A.A. Abou-hussein ◽

Wolfgang Linert

Keyword(s):

Cell Line ◽

Cancer Cell ◽

Theoretical Calculations ◽

Thermal Analyses ◽

Cancer Cell Line ◽

Cellular Growth ◽

Planar Geometry ◽

Square Planar ◽

Vis Spectroscopy

Aim and Objective: Platinum (II) and platinum (IV) of pyrophosphate complexes have been prepared and characterized to discover their potential as antitumor drugs. This study was conducted to prepare and characterize new ternary platinum (II) complexes with formamidine and pyrophosphate as an antitumor candidate. Materials and Methods: The complexes have been characterized by mass, infrared, UV-Vis. spectroscopy, elemental analysis, magnetic susceptibility, thermal analyses, and theoretical calculations. They have been tested for their cytotoxicity, which was carried out using the fastcolorimetric assay for cellular growth and survival against MCF-7 (breast cancer cell line), HCT- 116 (colon carcinoma cell line), and HepG-2 (hepatocellular cancer cell line). Results: All complexes are diamagnetic, and the electronic spectral data displayed the bands due to square planar Pt(II) complexes. The optimized complexes structures (1-4) indicated a distorted square planar geometry where O-Pt-O and N-Pt-N bond angles were 82.04°-96.44°, respectively. Conclusion: The complexes showed noticeable cytotoxicity and are considered as promising antitumor candidates for further applications.

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Structure of the complexes of ethylenediphosphinetetraacetic acid in solution

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19850445 ◽

1985 ◽

Vol 50 (2) ◽

pp. 445-453 ◽

Cited By ~ 2

Author(s):

Jana Podlahová ◽

Josef Šilha ◽

Jaroslav Podlaha

Keyword(s):

Metal Ion ◽

Carboxyl Groups ◽

Complex Solution ◽

Square Planar ◽

Weak Complexes ◽

Carboxylic Groups ◽

Uv Visible ◽

The Stability ◽

Tetrahedral Complexes ◽

Free Carboxyl

Ethylenediphosphinetetraacetic acid is bonded to metal ions in aqueous solutions in four ways, depending on the type of metal ion: 1) through an ionic bond of the carboxylic groups to form weak complexes with a metal:ligand ratio of 1 : 1 (Ca(II), Mn(II), Zn(II), Pb(II), La(III)); 2) through type 1) bond with contributions from weak interaction with the phosphorus (Cd(II)); 3) through coordination of the ligand as a monodentate P-donor with the free carboxyl groups with formation of 2 : 1 and 1 : 1 complexes (Cu(I), Ag(I)); 4) through formation of square planar or, for Hg(II), tetrahedral complexes with a ratio of 1 : 2 with the ligand as a bidentate PP-donor with the free carboxyl groups (Fe(II), Co(II), Ni(II), Pd(II), Pt(II)). On acidification of the complex solution, the first two protons are bonded to the carboxyl groups. The behaviour during further protonation depends on the type of complex: in complexes of types 1) and 2) phosphorus is protonated and the complex dissociates; in complexes of types 3) and 4) the free carboxyl groups are protonated and the phosphorus-metal bond remains intact. The results are based on correlation of the stability constants, UV-visible, infrared, 1H and 31P NMR spectra and magnetic susceptibilities of the complexes in aqueous solution.

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Interaction of ditertiary phosphines with phenyl- and 1-naphthyldithiocarbamatonickel(II)

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19851383 ◽

1985 ◽

Vol 50 (6) ◽

pp. 1383-1390

Author(s):

Aref A. M. Aly ◽

Ahmed A. Mohamed ◽

Mahmoud A. Mousa ◽

Mohamed El-Shabasy

Keyword(s):

Thermal Analysis ◽

Powder Diffraction ◽

Spin Structure ◽

Magnetic Measurements ◽

Mixed Ligand ◽

Mixed Ligand Complexes ◽

X Ray ◽

Square Planar

The synthesis of the following mixed ligand complexes is reported: [Ni(phdtc)2(dpm)2], [Ni(phdtc)2(dpe)2], [Ni(phdtc)2(dpp)3], [Ni(1-naphdtc)2(dpm)2], [Ni(1-naphdtc)2], and [Ni(1-naphdtc)2(dpp)2], where phdtc = PhNHCSS-, 1-naphdtc = 1-NaPhNHCSS-, dpm = Ph2PCH2PPh2, dpe = Ph2P(CH2)2PPh2, and dpp = Ph2P(CH2)3PPh2. The complexes are characterised by microanalysis, IR and UV-Vis spectra, magnetic measurements, conductivity, X-ray powder diffraction, and thermal analysis. All the mixed ligand complexes are diamagnetic, and thus a square-planar or square-pyramidal (low-spin) structure was proposed for the present complexes.

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Synthesis and Structure of a Clathrated Two-Dimensional Metal-Organic Framework: [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2·H2O (L = Bis(1-pyrazinylethylidene)hydrazine)

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20080024 ◽

2008 ◽

Vol 73 (1) ◽

pp. 24-31

Author(s):

Dayu Wu ◽

Genhua Wu ◽

Wei Huang ◽

Zhuqing Wang

Keyword(s):

Metal Organic Framework ◽

Channel Structure ◽

Two Dimensional ◽

X Ray Diffraction ◽

Guest Molecules ◽

X Ray ◽

Square Planar ◽

Metal Organic ◽

Aqueous Meoh ◽

Organic Framework

The compound [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2 was obtained by the reaction of Cd(ClO4)2, bis(1-pyrazinylethylidene)hydrazine (L) and 4,4'-bipyridine in aqueous MeOH. Single-crystal X-ray diffraction has revealed its two-dimensional metal-organic framework. The 2-D layers superpose on each other, giving a channel structure. The square planar grids consist of two pairs of shared edges with Cd(II) ion and a 4,4'-bipyridine molecule each vertex and side, respectively. The square cavity has a dimension of 11.817 × 11.781 Å. Two guest molecules of bis(1-pyrazinylethylidene)hydrazine are clathrated in every hydrophobic host cavity, being further stabilized by π-π stacking and hydrogen bonding. The results suggest that the hydrazine molecules present in the network serve as structure-directing templates in the formation of crystal structures.

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