Platinum organometallic complexes: classification and analysis of crystallographic and structural data of tri- and oligomeric complexes

2014 ◽  
Vol 34 (4) ◽  
pp. 247-279
Author(s):  
Milan Melník ◽  
Peter Mikuš ◽  
Clive E. Holloway

AbstractThis review covers almost 100 organoplatinum complexes: trimers (40 examples), tetramers (40 examples), pentamers (4 examples), hexamers (5 examples), nona- and oligomers (8 examples). Platinum is predominantly found in the oxidation states +2 and +4. A number of coordination geometries are observed, the most common being essentially square planar, especially with Pt(II), and distorted octahedral, especially with Pt(IV). The most common ligands are methyl, carbonyl, PX3 and bis(diphenylphosphine)methane. Relationships between the Pt-Pt distances, Pt-X-Pt bridge angles, Pt-L bond distances and covalent radii of coordinated atoms are discussed. The mean Pt-Pt bond distance elongates in the order of nuclearity: 269.0 pm (trimers)<270.5 pm (tetramers)<271.5 pm (dimers)<278.0 pm (oligomers). A comprehensive brief discussion on over 1600 organoplatinum complexes and over 2500 platinum coordination complexes is given. These complexes prefer to crystallize in monoclinic (53%) and triclinic (27%) crystal classes. About l0% of these 4100 plus complexes exist as isomers. It is observed that these isomers are more often stereoisomers than structural isomers and that distortion isomerism is surprisingly more common than the better known cis-trans isomerism, especially in the chemistry of Pt(II) complexes.

2014 ◽  
Vol 34 (1) ◽  
pp. 25-90 ◽  
Author(s):  
Milan Melník ◽  
Peter Mikuš ◽  
Clive Edward Holloway

AbstractThis review covers over 260 examples of dimeric organoplatinum complexes. Platinum is predominantly found in the oxidation states +2 and +4, but with some examples of 0, +1, +2.5, +3, and of mixed-valence as well. A number of coordination state geometries are observed, of which the most common is essentially square-planar at Pt(II), a distorted octahedral at Pt(IV), and some examples of trigonal planar and trigonal bipyramidal as well. The most common ligands are methyl (Me), carbonyl and PX3. The shortest Pt-Pt bond distance is 245.1(1) pm. The mean Pt-Pt bond distance increases in the order: 261.1 pm [Pt(2.5)-Pt(2.5)]<261.3 pm [Pt(III)-Pt(III)]<262.4 pm [Pt(I)-Pt(I)]<270.3 pm [Ot(II)-Pt(II)]<277.2 pm [Pt(0)-Pt(0)]<282.6 pm [Pt(II)-Pt(II)]. The Pt…Pt no-bonding distances are: Pt(II)…Pt(II), 3.008–17.959 pm; Pt(IV)…Pt(IV), 327.5–768.0 pm; Pt(II)-Pt(0), 378.6 pm and Pt(II)…Pt(IV), 389 pm. There are several relationships pointed out between the Pt-Pt distances, Pt-X-Pt bridge angles and covalent radii of coordinated atoms. Several examples contain two crystallographically independent molecules within the same crystal, differing mostly by degree of distortion, which are examples of distortion isomerism.


1972 ◽  
Vol 50 (3) ◽  
pp. 315-323 ◽  
Author(s):  
G. W. Bushnell ◽  
M. A. Khan

The crystal structure of dinitrato-2,2′-dipyridylsilver(II) has been solved and refined to an R-value of 0.070. Four circle diffractometer measurements were obtained from the twinned triclinic crystals. The unit cell dimensions at 22 °C are: a = 697.5 ± 0.2 pm, b = 999.4 ± 0.2 pm, c = 1032.2 ± 0.2 pm, α = 113.46 ± 0.02°, β = 100.71 ± 0.02°, γ = 95.28 ± 0.02°. The space group is [Formula: see text] (No. 2) with two molecules per unit cell. The density is 2.06 ± 0.04 g cm−3 (measured), 2.02 g cm−3 (calculated). The four shortest bond lengths to silver are: Ag—O(1), 214.8 ± 1.5 pm; Ag—O(4), 213.6 ± 1.5 pm; Ag—N(1), 212.4 ± 1.6 pm; Ag—N(2), 220.7 ± 1.6 pm. These four bonds are distorted from square planar geometry with the silver atom lying 19.90 ± 0.17 pm out of the mean plane of the other four atoms. There are also long bonds to the nitrato groups of neighboring molecules: Ag—O(1′), 275.3 ± 1.3 pm; Ag—O(2″), 276.3 ± 1.6 pm. Inclusion of these bonds gives a distorted octahedral silver coordination. Though predominantly unidentate, there is a slight tendency toward bidentate bonding in both nitrato ligands: Ag—O(2), 305.8 ± 1.4 pm; Ag—O(5), 295.0 ± 1.7 pm. O(2) and O(5) approach the convex side of the distorted square planar coordination. The deviation from planarity of the closely bonded square, and angular distortions in the above mentioned octahedral coordination can be rationalized by considering the silver as eight coordinate. The bonds to silver may be grouped 4:2:2 by length or 4:3:1 by angular disposition.


1993 ◽  
Vol 07 (17) ◽  
pp. 1133-1140 ◽  
Author(s):  
GERD BERGHÖFER ◽  
DIRK REINEN ◽  
GHULAM AKHTAR ◽  
JOSEF HORMES

X-ray absorption near edge spectra (XANES) have been measured on the Bi M 5 edge of the semiconducting perovskite-type solid solution Ba 1+x Bi 1−x O 3−δ (−0.43 ≤ x ≤ 0.43) and of superconducting Ba 0.6 K 0.4 BiO 2.93. The results are interpreted on the basis of the mean Bi valence as determined by iodometric analyses. The near edge spectra and the pre-edge features of the semiconducting samples show distinct differences ascribable to separate Bi(III) and Bi(V) oxidation states, in agreement with the structural results, and their relative intensities directly reflect the Bi(V) content. The spectrum of superconducting Ba 0.6 K 0.4 BiO 2.93 is comparable to the spectra of the semiconducting compounds with a similar Bi oxidation state, with an additional absorption about 20 eV beyond the absorption edge, however. Structural data are also presented.


2015 ◽  
Vol 35 (3) ◽  
pp. 135-149 ◽  
Author(s):  
Milan Melník ◽  
Peter Mikuš

AbstractThe coordination chemistry of platinum covers a huge field as shown by a recent survey covering the structural parameter of almost 460 dimeric to oligomeric examples. Approximately 10% of these complexes exist as isomers and are summarized in this review. Included are distortion (87%) and cis-trans (13%) isomers. These are discussed in terms of the coordination about the platinum atom, and correlations are drawn among donor atom, bond distance, and interbond angles. Distortion isomers, differing by a degree of distortion in Pt-L and Pt-Pt distances and L-Pt-L angles, and some also by crystal classes, are the most common. Distortion isomers are also spread over a wider range of oxidation states of platinum [0, +1, +2 (most common), +3, +4, and even nonintegral (+2.14 and +2.375)] than cis-trans isomers (+2 and +3 only). Surprisingly, distortion isomerism is more common than the better-known cis-trans isomerism in the chemistry of platinum.


2013 ◽  
Vol 33 (1) ◽  
pp. 13-103 ◽  
Author(s):  
Milan Melník ◽  
Peter Mikuš ◽  
Clive Eduard Holloway

AbstractFour hundred and twenty monomeric organoplatinum compounds, in which platinum atoms are five- and higher coordinated, are analyzed. The platinum atoms are found in the oxidation states +2, +3 and +4. The Pt(II) compounds by far prevail. There are wide varieties of the inner coordination spheres about the platinum centers. The Pt(II) compounds are five-coordinated (trigonal bipyramidal and square pyramidal), six-coordinated (different degrees of distortion), seven-coordinated (pentagonal bipyramidal, piano stool) and sandwiched (PtC10). The Pt(III) compound is square-planar. The Pt(IV) compounds are six- and eight-coordinated. There are several relationships between the Pt-L bond distances, covalent radii of the coordinated atom/ligand, and metallocycles, which are discussed. The trans-effect plays an important role in the inner coordination spheres about the Pt centers, especially on the Pt-L bond distances.


2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Milan Melník ◽  
Peter Mikuš ◽  
Clive E. Holloway

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.


2010 ◽  
Vol 8 (5) ◽  
pp. 965-991 ◽  
Author(s):  
Milan Melnik ◽  
Mária Kohútová

AbstractThe coordination chemistry of iron covers a wide field, as shown by a survey covering the crystallographic and structural data of almost one thousand and three hundred coordination complexes. About 6.7% of these complexes exist as isomers and are summarized in this review. Included are distortion (96.6%) and cis — trans (3.4%) isomers. These are discussed in terms of the coordination about the iron atom, bond length and interbond angles. Distortion isomers, differing only by degree of distortion in Fe-L, Fe-L-Fe and L-Fe-L parameters, are the most common. Iron is found in the oxidation states zero, +2 and +3 of which +3 is most common. The stereochemistry around iron centers are tetrahedral, five — coordinated (mostly trigonal — bipyramid) and six — coordinated. The most common ligands have O and N donor sites.


Author(s):  
Stanislav Chladek ◽  
Martin Trömel

AbstractBond-length-bond-strength relationships which are valid for different oxidation states of the elements have been established for oxides of As, Se, Br, Pb and Bi. According to new structural data, such relationships of single oxidation states in oxides of Ga(III), Ge(IV), In(III), Tl(I) and Tl(III) have been recalculated as well as those for oxides of Sn, Sb, Te, and I.


2006 ◽  
Vol 61 (10-11) ◽  
pp. 588-594 ◽  
Author(s):  
Basavalinganadoddy Thimme Gowda ◽  
Jozef Kožíšek ◽  
Hartmut Fuess

TMPAThe effect of substitutions in the ring and in the side chain on the crystal structure of N- (2,4,6-trimethylphenyl)-methyl/chloro-acetamides of the configuration 2,4,6-(CH3)3C6H2NH-COCH3− yXy (X = CH3 or Cl and y = 0,1, 2) has been studied by determining the crystal structures of N-(2,4,6-trimethylphenyl)-acetamide, 2,4,6-(CH3)3C6H2NH-CO-CH3 (); N-(2,4,6- trimethylphenyl)-2-methylacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH2-CH3 (TMPMA); N-(2,4,6- trimethylphenyl)-2,2-dimethylacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH(CH3)2 (TMPDMA) and N-(2,4,6-trimethylphenyl)-2,2-dichloroacetamide, 2,4,6-(CH3)3C6H2NH-CO-CHCl2 (TMPDCA). The crystallographic system, space group, formula units and lattice constants in Å are: TMPA: monoclinic, Pn, Z = 2, a = 8.142(3), b = 8.469(3), c = 8.223(3), β = 113.61(2)◦; TMPMA: monoclinic, P21/n, Z = 8, a = 9.103(1), b = 15.812(2), c = 16.4787(19), α = 89.974(10)◦, β = 96.951(10)◦, γ =89.967(10)◦; TMPDMA: monoclinic, P21/c, Z = 4, a =4.757(1), b= 24.644(4), c =10.785(2), β = 99.647(17)◦; TMPDCA: triclinic, P¯1, Z = 2, a = 4.652(1), b = 11.006(1), c = 12.369(1), α = 82.521(7)◦, β = 83.09(1)◦, γ = 79.84(1)◦. The results are analyzed along with the structural data of N-phenylacetamide, C6H5NH-CO-CH3; N-(2,4,6-trimethylphenyl)-2-chloroacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH2Cl; N-(2,4,6-trichlorophenyl)-acetamide, 2,4,6-Cl3C6H2NH-COCH3; N-(2,4,6-trichlorophenyl)-2-chloroacetamide, 2,4,6-Cl3C6H2NH-CO-CH2Cl; N-(2,4,6-trichlorophenyl)- 2,2-dichloroacetamide, 2,4,6-Cl3C6H2NH-CO-CHCl2 and N-(2,4,6-trichlorophenyl)- 2,2,2-trichloroacetamide, 2,4,6-Cl3C6H2NH-CO-CCl3. TMPA, TMPMA and TMPDCA have one molecule each in their asymmetric units, while TMPDMA has two molecules in its asymmetric unit. Changes in the mean ring distances are smaller on substitution as the effect has to be transmitted through the peptide linkage. The comparison of the other bond parameters reveal that there are significant changes in them on substitution.


2015 ◽  
Vol 71 (9) ◽  
pp. 1017-1021 ◽  
Author(s):  
Francisca N. Rein ◽  
Weizhong Chen ◽  
Brian L. Scott ◽  
Reginaldo C. Rocha

We report the structural characterization of [6′,6′′-bis(pyridin-2-yl)-2,2′:4′,4′′:2′′,2′′′-quaterpyridine](2,2′-bipyridine)chloridoruthenium(II) hexafluoridophosphate, [RuCl(C10H8N2)(C30H20N6)]PF6, which contains the bidentate ligand 2,2′-bipyridine (bpy) and the tridendate ligand 6′,6′′-bis(pyridin-2-yl)-2,2′:4′,4′′:2′′,2′′′-quaterpyridine (tpy–tpy). The [RuCl(bpy)(tpy–tpy)]+monocation has a distorted octahedral geometry at the central RuIIion due to the restricted bite angle [159.32 (16)°] of the tridendate ligand. The Ru-bound tpy and bpy moieties are nearly planar and essentially perpendicular to each other with a dihedral angle of 89.78 (11)° between the least-squares planes. The lengths of the two Ru—N bonds for bpy are 2.028 (4) and 2.075 (4) Å, with the shorter bond being opposite to Ru—Cl. For tpy–tpy, the mean Ru—N distance involving the outer N atomstransto each other is 2.053 (8) Å, whereas the length of the much shorter bond involving the central N atom is 1.936 (4) Å. The Ru—Cl distance is 2.3982 (16) Å. The free uncoordinated moiety of tpy–tpy adopts atrans,transconformation about the interannular C—C bonds, with adjacent pyridyl rings being only approximately coplanar. The crystal packing shows significant π–π stacking interactions based on tpy–tpy. The crystal structure reported here is the first for a tpy–tpy complex of ruthenium.


Sign in / Sign up

Export Citation Format

Share Document