A structural study of copper(II) carboxylates: Crystal structure and physical characterisation of [Cu2(2-bromopropanoato)4(caffeine)2]

Based on the bond-valence sum model the continual transition between the bidentate and monodentate bonding mode of carboxylato group and minimum of Cu-O bond lengths were estimated. The dependence of Cu⋯Cu separation on Cu-N bond length in binuclear Cu(II) carboxylates with caffeine were derived and fitted to the observed data. The crystal structure of [Cu2(2-bromopropanoato)4(caffeine)2] has been determined by X-ray crystallography. The structure consists of centrosymmetric binuclear units where the two Cu atoms are coordinated by four disordered bridging 2-bromopropionates and two caffeine ligands at the apices of a bicapped square prism. Both 2-bromopropionates show disorder of their -Br and -CH3 substituents. Stacking π·π interactions between the adjacent caffeine molecules link the complex units in 1-D networks. The binuclear structure of the studied compound is consistent with magnetic data and EPR spectru

Organodiphosphines in PtP2X2 (X = As, Ge or Te) derivatives – Structural aspects

Structural data of cis-Pt(η2-P2L)(XL)2 (X = Ge or Te), cis-Pt(η2-P2L)(η2-X2L) (X = As, Ge or Te) and trans-Pt(η2-P,TeL)2 were classified and analyzed. The chelating ligands create varieties of metallocyclic rings, which open in the sequence: 83.1° (GeGeGe) < 83.8° (AsC2As) < 86.2° (PC2P) < 88.5° (PC2Te) < 89.7° (PC3P) ~ 89.7° (GeGe2Ge). The structural data are compared and discussed with the complexes of an inner coordination spheres Pt(η2-P2L)(XL)2 (X = O, N, CN, B, Cl, S, Se, Si, Br or I), Pt(η2-P2L)(η2- X2L) (X = O, N, S, Se or Si), and Pt(η2-P,SiL)2

Heterotridentate Organomonophosphines in Pt(κ³–X¹P¹X²)(Y) (X^1,2 = N^1,2 or S^1,2), Pt(κ³–P¹N¹X¹)(Y) (X¹ = O, C, S or Se) Pt(κ³–P¹S¹Cl¹)(Cl) and Pt(κ³–P¹Si¹N¹)(OL)—Structural Aspects

This review covers twenty four Pt(II) complexes of the inner coordination sphere Pt(κ3–P1 N1N2)(Y), (Y = Cl, CL); Pt(κ3–P1N1X1)(Y), (X1 = O1 and Y = P2L, Cl, I); (X1 = C1 and Y = NL, Cl); (X1 = S1 and Y = Cl, I); (X1 = Se1 and Y = Cl); Pt(κ3–N1P1N2)(Cl), Pt(κ3–S1P1S2)(Cl), Pt(κ3–P1S1Cl1)(Cl) and Pt(κ3–P1Si1N1)(OL). These complexes are crystallized in three crystal classes: monoclinic (16 examples), triclinic (5 examples), and orthorhombic (3 examples). Each κ3–ligand creates two metallocyclic rings with various combinations of the respective metallocyclic rings. If the common central ligating atom is N1, the 5 + 5 membered, 5 + 5, 5 + 6, 6 + 5, and 6 + 6; if the common central ligating atom is P1: 5 + 5, and 6 + 6; if the common central ligating atom is S1 or Si1, 5 + 6-membered. The structural parameters (Pt-L, L-Pt-L) are analysed and discussed with an attention to the distortion of a square-planar geometry about the Pt(II) atoms as well as trans-influence. The sums of the Pt-L (x = 4) bond distances the growing with the covalent radius of the Y atoms. Noticeably, the distortion of the square-planar geometry is growing with the decreasing size of the inner coordination sphere about the Pt(II) atom. There is a relation between the degree of distortion (Ʈ4) and the numbers of the metallocycles rings. The distortion diminishing is in the order of: 0.058 (5 + 5) > 0.037 (6 + 5) > 0.023 (5 + 6) > 0.022 (6 + 6) membered

Structures of Pt(0)P3, Pt(0)P4 and Pt(II)P4 – Distortion isomers

In 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

A comprehensive view of metallocycles in Pt(η3–P1X1P2)(Y), derivatives-structural aspects

This review covers over one hundred Pt(II) complexes of the compositions Pt(&eta;3&ndash;P1X1P2)(Y), (X1 = O1L, N1L, C1L, B1L, S1L or Si1L) and (Y = H, F, Cl, Br, I, O2L, N2L, C2L, or P3L). These complexes crystallized in five crystal classes: monoclinic (60 examples), triclinic (36 examples), orthorhombic (13 examples), trigonal (1 example) and tetragonal (1 example). Each heterotridentate organodiphosphine creates two metallocyclic rings with a common X1 atom. There are fourteen types of metallocycles from which the P1C2X1C2P2 is most common. The structural parameters (Pt-L, L-Pt-L) are analyzed and discussed with attention to the distortion of a square-planar geometry about the Pt(II) atoms as well as of trans-influence

Structural Aspects of Pt(η³–P¹C₂X¹C₂P²)(Y) Derivative Types

In this structural study, structural data are classified and analyzed for almost seventy complexes of the general formula Pt(η3–P1X1P2)(Y) (X1 = O, N, C, S, Si) and (Y = various monodentate ligands), in which the respective η3–P1X1P2 ligand forms a pair of five-membered metallocyclic rings with a common X1 atom of the P1C2X1C2P2 type. The present complexes crystallize in five crystal systems: trigonal (1×), tetragonal (1×), orthorhombic (11×), triclinic (18×), and monoclinic (39×). In 69 complexes, a η3 ligand with monodentate Y constructs a distorted square planar geometry around each Pt(II) atom. There is only one complex in which Pt(η3–P1Si1P2)(P3Ph3) constructs a trigonal–pyramidal geometry around a Pt(II) atom. The three P atoms construct a trigonal plane, and the Si atom occupies a pyramid. The structural data are discussed from various points of view, including the covalent radii of the atoms, the degree of distortion, and trans-influence. The trans-effect on the Pt-L bond distance also affects the L-PT-L bond angles, as well as the distortion of square planar geometry around Pt(II) atoms