Coordinatively- and electronically-unsaturated square planar cobalt(iii) complexes of a pyridine dianionic pincer ligand

2017 ◽  
Vol 46 (46) ◽  
pp. 16228-16235 ◽  
Author(s):  
Faidh Hana ◽  
Alan J. Lough ◽  
Gino G. Lavoie

Coordinatively- and electronically-unsaturated cobalt(iii) complexes supported by a dianionic ligand were studied, resulting in the first structurally-characterized square-planar cobalt hydroxide complex.

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 119
Author(s):  
Jamal Lasri ◽  
Matti Haukka ◽  
Hessa H. Al-Rasheed ◽  
Nael Abutaha ◽  
Ayman El-Faham ◽  
...  

The square planar complex [Pd(PT)Cl(H2O)]*H2O (HPT: 6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4(1H,3H)-dione) was obtained by the reaction of 2-methoxy-4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine (MBPT) pincer ligand with PdCl2 in a molar ratio (1:1) under thermal conditions and using acetone as a solvent. The reaction proceeded via C-N cleavage of one C-N moiety that connects the pyrazole and s-triazine combined with the hydrolysis of the O-CH3 group. The reaction of the chloride salt of its higher congener (PtCl2) gave [Pt(3,5-dimethyl-1H-pyrazole)2Cl2]. The crystal structure of [Pd(PT)Cl(H2O)]*H2O complex is stabilized by inter- and intra-molecular hydrogen bonding interactions. Hirshfeld analysis revealed that the H...H (34.6%), O...H (23.6%), and Cl...H (7.8%) interactions are the major contacts in the crystal. The charges at Pd, H2O, Cl and PT are changed to 0.4995, 0.2216, −0.4294 and −0.2917 instead of +2, 0, −1 and −1, respectively, using the MPW1PW91 method. [Pd(PT)Cl(H2O)]*H2O complex has almost equal activities against MDA-MB-231 and MCF-7 cell lines with IC50 of 38.3 µg/mL.


2011 ◽  
Vol 50 (35) ◽  
pp. 8184-8187 ◽  
Author(s):  
Jenni Meiners ◽  
Markus G. Scheibel ◽  
Marie-Hélène Lemée-Cailleau ◽  
Sax A. Mason ◽  
M. Bele Boeddinghaus ◽  
...  

2015 ◽  
Vol 21 (2) ◽  
pp. 474-474
Author(s):  
Bjorn Askevold ◽  
Marat M. Khusniyarov ◽  
Wolfgang Kroener ◽  
Klaus Gieb ◽  
Paul Müller ◽  
...  

2019 ◽  
Vol 58 (2) ◽  
pp. 1252-1266 ◽  
Author(s):  
Brett M. Hakey ◽  
Jonathan M. Darmon ◽  
Yu Zhang ◽  
Jeffrey L. Petersen ◽  
Carsten Milsmann

2014 ◽  
Vol 21 (2) ◽  
pp. 579-589 ◽  
Author(s):  
Bjorn Askevold ◽  
Marat M. Khusniyarov ◽  
Wolfgang Kroener ◽  
Klaus Gieb ◽  
Paul Müller ◽  
...  

2020 ◽  
Vol 76 (11) ◽  
pp. 1741-1747
Author(s):  
H. V. Rasika Dias ◽  
Abhijit Pramanik

The synthesis, isolation and crystal structures of nickel(II) carbonyl, acetonitrile and ammonia complexes supported by a dianionic, pyridine dipyrrolide pincer ligand [pyrr2py]2−, namely, carbonyl[2,2′-(pyridine-2,6-diyl)bis(3,5-di-p-tolylpyrrolido-κN)]nickel(II), [Ni(C41H33N3)(CO)], ammine[2,2′-(pyridine-2,6-diyl)bis(3,5-di-p-tolylpyrrolido-κN)]nickel(II), [Ni(C41H33N3)(NH3)], and (acetonitrile-κN)[2,2′-(pyridine-2,6-diyl)bis(3,5-di-p-tolylpyrrolido-κN)]nickel(II), [Ni(C41H33N3)(CH3CN)], as well as the free ligand 2,6-bis(3,5-di-p-tolylpyrrol-2-yl)pyridine, C41H35N3 or [pyrr2py]H2 are reported. The nickel complexes are four-coordinate and adopt a square-planar geometry. The CO stretch of the nickel-bound carbon monoxide ligand of [pyrr2py]Ni(CO) has been observed at 2101 cm−1. The ammonia and acetonitrile complexes, [pyrr2py]Ni(NH3) and [pyrr2py]Ni(NCMe) feature all-nitrogen coordination spheres around nickel consisting of different N-donor ligand types.


Author(s):  
Maryvonne Hervieu

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.


2018 ◽  
Author(s):  
Tasneem Siddiquee ◽  
Abdul Goni

Chemical treatment of CoX<sub>2</sub><b><sup>. </sup></b>6H<sub>2</sub>O (X = Cl, Br, I) with the potentially tridentate PNP pincer ligand 2,6-bis(di-<i>tert</i>-butylphosphinomethyl)pyridine in 1:1 molar ratio results in cobalt(II) halide-PNP pincer complexes. The effect of the hydrated metal source on molecular structure and geometry of the complexes was studied by single crystal X-ray diffraction analysis. The complexes are neutral and the cobalt center adopts a penta-coordinate system with potential atropisomerization. Within the unit cell there are two distinct molecules per asymmetric unit. One of the two phosphorus atoms in the PNP ligand was observed to be partially oxidized to phosphinoxide. Disorder in the structure reflects a mixture of square pyramidal and distorted tetrahedral geometry.


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

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.


1985 ◽  
Vol 50 (2) ◽  
pp. 445-453 ◽  
Author(s):  
Jana Podlahová ◽  
Josef Šilha ◽  
Jaroslav Podlaha

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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