scholarly journals Variable combinations of organophosphines in PtP3X derivatives: Structural aspects

2020 ◽  
Vol 44 (1) ◽  
pp. 12-21
Author(s):  
Milan Melník ◽  
Peter Mikuš

Abstract This review covers over fifty Pt (II) complexes of the compositions PtP3X (X = H, OL, NL, BL, Cl, SL, Br, or I). These complexes crystallized in three crystal classes: monoclinic (23 examples) triclinic (17 examples) and orthorhombic (11 examples). The PtP3Cl is most common with 23 examples. There are variable combinations of organophosphines monodentate – P; bidentate- P,P; P,N; P,B; and tridentate – P,P,P; P,O,P; P,N,P; and P,S,P. The structural parameters (Pt–L, L–Pt–L) are analyzed and discussed with an attention to the distortion of a square-planar geometry about the Pt (II) atoms as well as of trans-influence. The sums of Pt–L (x4) bond distances growing with covalent radius of the X-atoms.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Milan Melník ◽  
Peter Mikuš

Abstract This review covers almost 30 Pt(II) complexes of the composition Pt(η3-P1X1P2)(Y), (X1 = BL, SL, or SiL), (Y = H, OL, NL, CL, Cl, PL, or I) and Pt(η3-P1P2Si1)(CH3). Heterotridentate ligands form six types of metallocyclic rings: P1CNB1NCP2, P1C2S1C2P2, P1C2Si1C2P2, (most common), P1CNSi1NCP2, and P1C3Si1C3P2 with common B1, S1, or Si1 atoms. In P1C2P2C3Si1 the P2 atom is common. The structural data (Pt–L, L–Pt–L) are analyzed and discussed with an attention to the distortion of a square-planar geometry about Pt(II) atoms as well as trans-influence. The sum of Pt–L(x4) bond distances growing with covalent radius of the X1 and Y atoms.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Milan Melník ◽  
Peter Mikuš

AbstractIn this review, the structural parameters of distortion isomers of cis-monomeric Pt(II) coordination complexes with inner coordination spheres: Pt(PL)2X2 (X = OL, NL, SL, Br, I); Pt(PL)2(η2-X2L) (X = O2L, N2L, S2L, OSL, NSL, NSeL); Pt(η2-P2L)X2 (X = Br, I); Pt(η2-P2L)(η2-X2L) (X = O2L, OSL, NSL); Pt(η2-P2L)(NL)(Cl) and Pt(PL)(η2-P,SiL)(H) are analyzed. None of the distortion isomers with cis-configuration has a trans-partner. The distortion isomers differ mostly by the degree of distortion in the Pt-L and L-Pt-L angles. Some of the isomers also differ by crystal packing. The total mean values of Pt-P (monodentate) and Pt-P (bidentate) bond distances are 2.279 Å and 2.244 Å, respectively. The mean value of Pt-P (monodentate) (trans to H¯) of 2.320 Å is the highest one because of higher trans-influence of H¯ over PP3. The total mean values of Pt-X (trans to P) elongate quite well with the covalent radius of the X in the sequence: 1.57 Å (X = H) < 2.062 Å (O2L) < 2.095 Å (OL) < 2.108 Å (NL) < 2.154 Å (N2L) < 2.329 Å (Cl) < 2.342 Å (S2L) < 2.347 Å (SL) < 2.480 Å (Br) < 2.616 Å (I).


2004 ◽  
Vol 59 (6) ◽  
pp. 655-660 ◽  
Author(s):  
Pritha Talukder ◽  
Amitabha Datta ◽  
Samiran Mitra ◽  
Georgina Rosair

The title compounds, [Cu(C16H23N2O)SCN] (1) and [Cu(C16H23N2O)N3] (2), containing a tridentate Schiff base ligand, which is the 1:1 condensation product of benzoylacetone and 2- diethylaminoethylamine, have been synthesised and their crystal structures determined. The structure of 1 is based on a four coordinate copper centre with square-planar geometry formed by the N2O donor set of the Schiff base and an N atom of the thiocyanate anion. A similar arrangement occurs in 2 with the N2O donor set of the Schiff base and an N atom of the azide anion. The Cu-N and Cu-O distances are 1.924(8), 2.073(8), 1.927(9) and 1.910(6)Å , for 1 and 1.960(4), 2.050(4), 1.935(4) and 1.907(3) for 2, respectively.


2020 ◽  
Vol 43 (1) ◽  
pp. 111-116
Author(s):  
Milan Melník ◽  
Peter Mikuš

AbstractIn this review are analyzed and classified crystallographic and structural parameters of P(0)P3, Pt(0) P4 and Pt(II)P4 derivatives – distortion isomers. Some of the isomers are differing not only by degree of distortion but also by crystal class. There are three types of organo-phosphines which build up the respective geometry about the platinum atoms. In Pt(0)P3 a distorted trigonal planar geometry is build up by three monodentate PPh3 ligands. In Pt(0)P4 a tetrahedral geometry with various degree of distortion is build up by a pair of homo-bidentate ligands. In Pt(II)P4 isomers a square-planar geometries with various degree of distortion are build up by bidentate-P,P’donor ligands, (except one example of isomers, where a tetradentate is involved). The bidentate-P,P’-donor ligands form: four-(PNP,PCP), five-(PC2P) and six-(PC3P) metallocyclic rings. The tetradentate forms five-(PC2P). There are some cooperative effects between Pt–P bond distances and the metallocyclic rings, and at the same time a distortion of the respective geometry increases.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Milan Melník ◽  
Peter Mikuš

Abstract This review covers over 30 examples of monomeric Pt(II) complexes of the types: Pt(η3–P1O1P2)(Y) (Y = PL, CL, OL), Pt(η3–P1N1P2)(Y) (Y = H, NL, CL, Cl, PL) and Pt(η3–P1P2N1)(Y) (Y = Cl). The heterotridentate donor ligands create 11 types of a couple chelate rings with common central atom O1 (η3–P1O1P2), N1 (η3–P1N1P2) and P2 (η3–P1P2N1). The most frequent is P1C2N1C2P2. Some cooperative effects between chelate rings and Y donor ligands were found and discussed. A degree of distortions of square-planar geometry about Pt(II) were also calculated.


2021 ◽  
Vol 44 (1) ◽  
pp. 270-280
Author(s):  
Milan Melník ◽  
Peter Mikuš

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.


1999 ◽  
Vol 77 (9) ◽  
pp. 1492-1497 ◽  
Author(s):  
Sandra Signorella ◽  
Claudia Palopoli ◽  
Alejandro Frutos ◽  
Graciela Escandar ◽  
Tomoaki Tanase ◽  
...  

The 3-deoxy-D-erythro-hexos-2-ulose bis(thiosemicarbazone) (LH2) acts as a tetradentate ligand with S2N2 donor sites to form a copper(II) chelate (Cu(II)L). The Cu K-edge X-ray absorption spectra analysis of a powdered sample revealed a square-planar S2N2 local coordination geometry with average Cu—N and Cu—S distances of 1.92 and 2.33 Å. The EXAFS and XANES spectra and the structural parameters of a DMF solution sample indicate the retention of the square-planar local structure of the Cu(II)S2N2 chromophore upon dissolution. Semiempirical PM3 calculations indicate that the structure of Cu(II)L with the copper(II) ion bound to the S2N2 donor set disposed in a square-planar geometry is the most favorable one (with the highest |ΔHf |). The formation constant (log Kf = 20.65 ± 0.06) of the neutral [CuL] species was calculated in 30% v/v dioxane-water and the protonation and deprotonation constants determined.Key words: bis(thiosemicarbazone), copper(II), chelate, structure, stability constant.


2020 ◽  
Vol 44 (19) ◽  
pp. 7976-7986 ◽  
Author(s):  
Athanassios C. Tsipis

trans-Philicity ladders for trans-Pt(PMe3)2(X)L (X = H, CH3, CO, NH2, OH2, Cl) complexes are built by σiso X NMR descriptors. Correlations of the σiso X vs popular electronic/structural parameters of L and X demonstrate the origin of trans philicity.


2021 ◽  
Vol 12 (6) ◽  
pp. 7804-7816

In this study, we report the synthesis, characterization, and biological activity of Pd-NHC-PEPPSI complex 2a. Further confirmations of structural details were provided by a single-crystal X-ray. A single crystal of 2a shows that the coordination geometry around Pd slightly distorted square-planar geometry. Intermolecular interactions have been studied through the NBO analyses. Structural parameters and spectroscopic properties of the complexes are well interpreted by DFT and TD-DFT calculations. Moreover, the complex 2a showed a remarkable antimicrobial effect against Micrococcus luteus LB 14110mm, Listeria monocytogenes ATCC 19117, Salmonella typhimurium ATCC 14028, Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa, and Candida albicans.


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.


Sign in / Sign up

Export Citation Format

Share Document