scholarly journals Tetradentate organophosphines in Pt(η4–A4L) (A = P4, P3Si, P2X2 (X2 = N2, S2, C2), PX3 (X3 = N3, N2O)): Structural aspects

2021 ◽  
Vol 44 (1) ◽  
pp. 270-280
Author(s):  
Milan Melník ◽  
Peter Mikuš
Keyword(s):  
Structural Characterization ◽  
Platinum Complexes ◽  
Planar Geometry ◽  
Bond Angles ◽  
Pyramidal Geometry ◽  
Tetradentate Ligands ◽  
Square Planar ◽  
Structural Aspects

Abstract We report herein structural characterization of monomeric platinum complexes of the composition: Pt(η4–P4L), Pt(η4–P3SiL), Pt(η4–P2N2L), Pt(η4–P2S2L), Pt(η4–P2C2L), Pt(η4–PN3L), and Pt(η4–PN2OL). The tetradentate ligands with 10-, 11-, 12-, 14-, and 16-membered macrocycles create a variety of chelate bond angles. A distorted square-planar geometry about Pt(II) atoms with cis–configuration by far prevail. There is an example Pt(η4–P3SiL) in which the respective donor atoms build up a trigonal-pyramidal geometry about Pt(II) atom.

scholarly journals Synthesis and Characterization of Catecholato Copper(II) Complexes with Sterically Hindered Neutral and Anionic N3 Type Ligands: Tris(3,5-diisopropyl-1-pyrazolyl)methane and Hydrotris(3,5-diisopropyl-1-pyrazolyl)borate

Inorganics ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 37 ◽  
Author(s):  
Kiyoshi Fujisawa ◽  
Tetsuya Ono ◽  
Moemi Okamura
Keyword(s):  
Planar Geometry ◽  
X Ray ◽  
Pyramidal Geometry ◽  
Square Planar ◽  
Ct Transitions ◽  
Sterically Hindered ◽  
Protonated Ligand ◽  
Square Pyramidal Geometry ◽  
Oxidation State Of Copper

Three catecholato copper(II) complexes, [Cu(catCl4)(L1′)], [Cu(catBr4)(L1′)], and [Cu(catCl4)(L1H)], supported by sterically hindered neutral and anionic N3 type ligands: tris(3,5-diisopropyl-1-pyrazolyl)methane (referred to as L1′) and hydrotris(3,5-diisopropyl-1-pyrazolyl)borate (referred to as L1−), are synthesized and characterized in detail. Their X-ray structures reveal that both [Cu(catCl4)(L1′)] and [Cu(catBr4)(L1′)] complexes have a five-coordinate square-pyramidal geometry and [Cu(catCl4)(L1H)] complex has a four-coordinate square-planar geometry. The L1H is unusual protonated ligand that controls its overall charge. For the three catecholato copper(II) complexes, the oxidation state of copper is divalent, and catechol exists in catecholate as two minus anion. This difference in coordination geometry affects their d-d and CT transitions energy and ESR parameters.

scholarly journals Crystallographic and structural characterization of heterometalic platinum complexes Part X. Heteropolynuclear pt complexes

2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Milan Melník ◽  
Peter Mikuš ◽  
Clive E. Holloway
Keyword(s):  
Transition Metals ◽  
Structural Characterization ◽  
Bond Distance ◽  
Platinum Complexes ◽  
Square Planar ◽  
The Mean

AbstractThis review covers heteropolynuclear platinum complexes. There are over sixty examples with heterometal atoms as partners including non- transition metals, K, Cs, Mg, Ca, Sr, Tl, Sn, Pb, Zn, Cd, and transition metals: Cu, Ag, Fe, Co, Ni, Rh and Pd. In addition, there are examples for the lanthanides, Eu and Yb. The most common are Ag (x16) and K (x14). The predominant geometries for Pt(II) is square-planar and for Pt(IV) is octahedral. The overall structures are complex. In spite of the wide variety of heterometal atoms partners of platinum, there is “real” Pt-M bonds only with silver, ranging from 2.678 to 2.943(I) Å (ave 2.855 Å). The mean Pt-Pt bond distance is 2.869 Å.

Synthesis and structural characterization of cobalt(III) complexes of hybrid donor-type didentate or tetradentate ligands bearing dimethylphosphino and thioether groups

Polyhedron ◽  
1998 ◽  
Vol 17 (11-12) ◽  
pp. 1817-1829 ◽  
Author(s):  
Kazuo Kashiwabara ◽  
Norihiko Taguchi ◽  
Hideo D. Takagi ◽  
Kiyohiko Nakajima ◽  
Takayoshi Suzuki
Keyword(s):  
Structural Characterization ◽  
Tetradentate Ligands ◽  
Donor Type

scholarly journals Crystallographic and structural characterization of heterometallic platinum compounds. Part II. Heterobinuclear Pt compounds with Pt⋯M (M = transition or lantanide metal) > 3.0 Å

2012 ◽  
Vol 10 (6) ◽  
pp. 1709-1759 ◽  
Author(s):  
Milan Melnik ◽  
Ondrej Sprusansky ◽  
Clive Holloway
Keyword(s):  
Transition Metal ◽  
Chlorine Atom ◽  
Structural Characterization ◽  
Platinum Compounds ◽  
Factors Affecting ◽  
Bond Lengths ◽  
Trigonal Bipyramidal ◽  
Square Planar ◽  
Independent Molecules

AbstractThis review covers almost two hundred and twenty heterobinuclear platinum compounds in which Pt⋯M separation is over 3.0 Å. The M is a transition metal (Cu, Ag, Au, Ti, V, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni and Pd). There is an example of a lanthanide, Yb and a actinide, U. The Pt atom has oxidation numbers 0, +2 and +4. The Pt coordination geometries include trigonal planar Pt(0); square planar Pt(II); trigonal bipyramidal, and pseudo octahedral Pt(IV), with the most frequent being square planar. The most common ligands for Pt are P and C donor atoms, as well as a chlorine atom. The Pt — Ag distance of 3.002(1) Å is the shortest found in this series. There are examples which contain two crystallographically independent molecules, which differ mostly by degree of distortion and even one unique example, which contains eight such molecules. These are examples of distortion isomerism. Factors affecting bond lengths and angles are discussed and some ambiguities in coordination polyhedral are outlined.

Design and Characterization of New Dinuclear Macrocyclic Dithiocarbamate Complexes by the Preparation of a Free Ligand Derived from Isopropylamine

2021 ◽  
pp. 1-15
Author(s):  
Noor Al-Huda A.H Al-Mohammadi ◽  
Aeed S.M Al-Fahdawi ◽  
Sattar S.I Al-Janabi
Keyword(s):  
Free Ligand ◽  
13C Nmr Spectroscopy ◽  
Macrocyclic Complexes ◽  
Planar Geometry ◽  
Basic Solution ◽  
Square Planar ◽  
Dithiocarbamate Ligand ◽  
Schiff Base Formation ◽  
Base Formation

The synthesis and structural characterization of new dithiocarbamate (DTC) ligand and some of its dinuclear transition metal complexes are described. The free dithiocarbamate ligand was prepared through several synthetic routes, including Schiff-base formation. The reaction of 2-aminopropane with terephthaldehyde leads to the formation of Schiff_base which is reduced by methanolic NaBH4 to the corresponding secondary diamine. Diamine( N,N'_ (1,4 phenylenebis (methylene)) bis(propan-2 amine))  reacts with (CS2) in a basic solution of (KOH) to provide the corresponding bis(dithiocarbamate) free_ligand, which undergoes complexation with the appropriate metal   (II) chloride to constitute macrocyclic complexes. Characterization of the ligand and its complexes was achieved by FTIR, UV-Vis, melting points, conductance, magnetic susceptibility, and 1H, 13C NMR spectroscopy. The analytical and spectroscopic data were employed to obtain the suggested geometries around metal centres. These studies revealed the formation of dinuclear macrocyclic complexes of the general formula [M(L)]2 (where M= Mn(II) , Fe(II), Co(II), Ni(II), Cu(II)  and Zn(II)), with tetrahedral. geometries for Mn(II) , Fe(II), Co(II) and Zn(II),  and square. planar geometry with Ni(II) and Cu(II) complexes.

scholarly journals Reaction with Proteins of a Five-Coordinate Platinum(II) Compound

2019 ◽  
Vol 20 (3) ◽  
pp. 520 ◽  
Author(s):  
Giarita Ferraro ◽  
Tiziano Marzo ◽  
Maria Cucciolito ◽  
Francesco Ruffo ◽  
Luigi Messori ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Platinum Complexes ◽  
Rnase A ◽  
Side Chain ◽  
Planar Geometry ◽  
Ionization Mass ◽  
X Ray ◽  
X Ray Crystallography ◽  
Egg White Lysozyme ◽  
Square Planar

Stable five-coordinate Pt(II) complexes have been highlighted as a promising and original platform for the development of new cytotoxic drugs. Their interaction with proteins has been scarcely studied. Here, the reactivity of the five-coordinate Pt(II) compound [Pt(I)(Me) (dmphen)(olefin)] (Me = methyl, dmphen = 2,9-dimethyl-1,10-phenanthroline, olefin = dimethylfumarate) with the model proteins hen egg white lysozyme (HEWL) and bovine pancreatic ribonuclease (RNase A) has been investigated by X-ray crystallography and electrospray ionization mass spectrometry. The X-ray structures of the adducts of RNase A and HEWL with [Pt(I)(Me)(dmphen)(olefin)] are not of very high quality, but overall data indicate that, upon reaction with RNase A, the compound coordinates the side chain of His105 upon releasing the iodide ligand, but retains the pentacoordination. On the contrary, upon reaction with HEWL, the trigonal bi-pyramidal Pt geometry is lost, the iodide and the olefin ligands are released, and the metal center coordinates the side chain of His15 probably adopting a nearly square-planar geometry. This work underlines the importance of the combined use of crystallographic and mass spectrometry techniques to characterize, in detail, the protein–metallodrug recognition process. Our findings also suggest that five-coordinate Pt(II) complexes can act either retaining their uncommon structure or functioning as prodrugs, i.e., releasing square-planar platinum complexes as bioactive species.

scholarly journals Transition metal complexes with thiosemicarbazide-based ligands. Part 60. Reactions of copper(II) bromide with pyridoxal S-methylisothiosemicarbazone (PLITSC). Crystal structure of [Cu(PLITSC−H)H2O]Br•H2O

2014 ◽  
Vol 79 (3) ◽  
pp. 291-302 ◽  
Author(s):  
Vukadin Leovac ◽  
Ljiljana Vojinovic-Jesic ◽  
Sonja Ivkovic ◽  
Marko Rodic ◽  
Ljiljana Jovanovic ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Elemental Analysis ◽  
Structural Characterization ◽  
Electronic Spectra ◽  
Square Planar

The synthesis and structural characterization of a square-planar copper(II) complex with pyridoxal S-methylisothiosemicarbazone (PLITSC) of the formula [Cu(PLITSC?H)H2O]Br?H2O (1) as the first Cu(II) complex with monoanionic form of this ligand were described. Complex 1 together with two previously synthesized complexes [Cu(PLITSC)Br2] (2) and [Cu(PLITSC)Br(MeOH)]Br (3) were characterized by elemental analysis, IR and electronic spectra and also by the methods of thermal analysis, conductometry and magnetochemistry.

Synthesis and Characterization of Palladium(II) Complexes with Substituted Dihydrobenzoimidazoquinazoline Derivatives

2016 ◽  
Vol 15 (2) ◽  
pp. 17-32
Author(s):  
Rita Bhattacharjee
Keyword(s):  
Thermal Analysis ◽  
Biological Activity ◽  
Mass Spectra ◽  
Molar Conductivity ◽  
Synthesis And Characterization ◽  
Planar Geometry ◽  
Conductivity Measurements ◽  
Square Planar

A series of palladium(II) halo complexes of the types[PdX2L2].nH2O {n = 0, X = Cl, L = L4and L6; X = Br, L = L3,L4, L5 and L6; n = 2, X = Cl, L = L3and L7, X = Br, L = L1};Pd2X4L2 {X = Cl, Br, L = L2 and L8} and Pd2X4L3 [X = Cl, L= L1; X = Br, L = L7] were prepared where L is 6-R-5,6-dihydrobenzoimidazo quinazoline (R-Diq; where R =phenyl: L1/furyl: L2/thiophenyl: L3/o- or phydroxyphenyl: L4, L5/o- or p-chlorophenyl: L6,L7/dimethylaminophenyl: L8and characterized byelemental analyses, molar conductivity measurements,TGA, infrared, electronic, NMR and mass spectraltechniques. Based on these studies, monomeric/dimericstructure with a square planar geometry around the metalion was proposed for these complexes. Anti-microbialactivity for some of the synthesized complexes wereinvestigated.Keywords: dihydrobenzoimidazoquinazoline, palladium(II),thermal analysis, mass spectra, biological activity.

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