Distortion Isomerism Research Articles

Organomonophosphines in Pt(η3-X1X2X3)(PR3), (X = N1, N2, N3; S1, S2, S3; or Te1, Te2, Te3) Derivatives: Structural Aspects

This paper covers nineteen Pt(II) complexes of the composition Pt(η3-X1X2X3)(PR3), (X = N1, N2, N3; S1, S2, S3; or Te1, Te2, Te3). These complexes crystallized in three crystal classes: triclinic (eleven examples), monoclinic (six examples), and orthorhombic (two examples). Each tridentate ligand creates two metallocyclic rings with common N2, S2, or Te2 donor ligands of the types N1C2N2C2N3, N1C2N2NC2N3, S1C2S2C2S3, S1C3S2C3S3, and Te1CNTe2NCTe3. The homotridentate ligand with monodentate PR3 ligand builds up a distorted square planar geometry about Pt(II) atoms. The degree of distortion ranges from 0.029 to 0.092, and the reason for the distortion is discussed. There is an example that contains two crystallographically independent molecules within the same crystal. This is a classic example of distortion isomerism.

Pyridine-2,6-dicarboxylates in monomeric iron complexes – structural aspects

AbstractThis review includes 70 monomeric high-spin complexes of the following general compositions: [Fe(II)(η3-pdc)(L)3], [Fe(III)(η3-pdc)(L)3]+, [Fe(II)(η3-pdc)2]2− and [Fe(III)(η3-pdc)2]− (pdc = pyridine-2,6-dicarboxylate (−2)). Each Fe(II) atom has a distorted octahedral geometry. The Fe(III) atoms have a distorted octahedral geometry (most common) and in some examples have a distorted pentagonal-bipyramidal geometry. The chelating donor ligands create varieties of n-membered metallocyclic rings: ONO, OCO, NC2N, OC2N, OC2NO and OC3O. Some cooperative effects between Fe(II) and Fe(III) complexes were found and discussed. There are complexes that are examples of distortion isomerism.

Crystal structures and Hirshfeld surface analysis of (cat)2[FeIII(η3-dipic)(NCS)3] and (cat)[FeIII(η3-dipic)(H2O)(NCS)2] (dipic = dipicolinate)

Crystal and molecular structures of black (cat)2[FeIII(η3-dipic)(NCS)3] (cat = C9H7NH; C10H9NH); (HNC10H8NH)[FeIII(dipic)(NCS)3], and (C6H7NH)[FeIII(η3-dipic)(H2O)(NCS)2] (dipic pyridine-2,6-dicarboxylate (−2); C9H7NH = quinolinium; C10H9NH = 3-methylisoquinolinium; HNC10H8NH = 4,4-bipyridinium; C6H7NH = 2-picolinium) were determinated. These complexes crystallized in monoclinic crystal class. Each Fe(III) atom is six coordinated. The octahedron is build up unsymmetrically, one half side is creates by terdentate dipic–1O,2N,3O ligand and the other half by three monodentate (NCS)3 or (NCS)2(H2O) donor ligands. The terdentate dipic–1O,2N,3O ligand forms a pair of five-membered metallocyclic rings with the common central 2N atom of pyridine (1OC22NC23O) with the mean value of O–Fe–N bite angles of 75.5°. The mean value of trans1O–Fe–3O bond angles is 150.8° in complexes with an inner coordination spheres FeO2N4 and FeO3N3. The mean value of sum of all three ((Fe–1O) + (Fe–2N) + (Fe–3O)) bond distances is 6.217 Å (FeO2N4) and 6.183 Å (FeO3N3). The opposite side in FeO2N4 is created by three monodentate NCS groups with the sum of Fe–N(x3) bond distances of 6.050 Å and in the FeO3N3 two NCS groups with water create opposite side with the sum of (Fe–N(x2) + Fe–O) bond distances of 6.183 Å. One polymorph of complex (C10H9NH)2[FeIII(dipic)(NCS)3] contains two crystallographically independent molecules differ mostly by degree of distortion in Fe–L bond distances and L–Fe–L bond angles and are examples of distortion isomerism. The data of the complexes are compare and discuses with the data of familiar iron(III) complexes. The intermolecular interactions of all compounds are studied by Hirshfeld surface analysis.

Stereoisomers of Pt(PL)2Cl2 derivatives – structural aspects

AbstractThe coordination complexes of Pt(PL)2Cl2type (PL = monodentate P-donor ligands) cover almost 260 examples as shown by a recent survey covering the crystallographic and structural data. About 20% of these complexes exist as isomers and are summarized in this review. Included are distortion (58.5%),cis-,trans- (37.8%) and mixed isomerism (cis-,trans- and distortion) (3.7%). Distortion isomers, differing by degree of distortion in Pt-L and L-Pt-L angles, are the most common. For these derivatives the most commoncis- arranged with 31 examples and 22 examples withtrans- arranged. The complexes withcis-configuration are more distorted than theirtrans-partners, with the comprehensive values of Pt-L bond distances: 2.246 Å (P) and 2.350 Å (Cl). Such values in the complexes withtrans-configurations are 2.323 Å (P) and 2.308 Å (Cl), respectively. These are discussed with attention to anytrans-influence.

ORGANODIPHOSPHINES IN PtP2X2 (X = Br or I) DERIVATIVES – STRUCTURAL ASPECTS

Baeyer-VillThis review covers twenty eight monomeric Pt(η2-P2L)X2 (X = Br or I) derivatives. These complexes exist in cis- as well as trans-configurations from which the complexes with cis-configuration are more common. The organodiphosphines create wide varieties of the metallocyclic rings PNP, PC2P, PC3P, PNCNP and PC4OC4P. The mean values of Pt-L bond distances in cis-complexes are: 2.230 A (P), 2.490 A (Br) and 2.240 A (P) 2.666A (I), respectively. In the trans-complexes the values are 2.319 A (P), 2.429 A (Br) and 2.320 A (P), 2.615 A (I). The Pt-X bond distances in the cis- as well as in the trans-derivatives elongate with the covalent radius of the X atom. In addition in the cis-derivatives the Pt-X bond distances are longer than those in trans-derivatives, as a reason of higher trans-influence of P over the respective halogens. Some of the complexes are examples of distortion isomerism. Finally, the structural data of Pt(η2-P2L)X2 (X = Br or I) are compared with the values of Pt(η2-P2L)X2, complex and discussed.

Structural aspects of heterooligonuclear platinum clusters – distortion isomers

Abstract This review covers 15 clusters of the compositions Pt3Re2, Pt2Os3, Pt3AgAu, Pt3Ir3, Pt2M4 (M=Ag or Pd), PtM5 [M=Ru (×2) or Os], Pt3Os4, Pt6Au2, Pt2Ru6, Pt3Ru6, Pt2Ru8, and PtAu9. Each of the cluster contains two crystallographically independent molecules that differ mostly by degree of distortion and are classical examples of distortion isomerism. Their structures are very complex. The inner coordination spheres about the metal atoms (Pt and M) are very complex as well. The clusters are rich in metal-metal bond distances with the shortest being 2.573 Å (Pt-Au), 2.615 (Pt-Pt), and 2.673 Å (Ru-Ru).

Structural aspects of heterotrinuclear Pt2M, PtM2, and PtMM′ complexes – distortion isomers

Abstract In this review, the structural parameters of 18 heterotrinuclear Pt2M (M=Hg, Zn, Cd, Au, Mn, Ag, Pd), PtM2 (M=Al, Ga, Sb, In, Mo, Fe), PtFeMn, PtHgMn, and PtFeOs types are summarized and analyzed. The Pt atoms are four-, five-, and even six-coordinated, among which the four-coordinated ones are the most common. The M atoms are found to be two- (Hg), three- (Hg), four- (Hg, Sb, In, Ag, Au), and six- (Ga, In, Al, Mo, Mn, Fe, Pd) coordinated and even sandwiched (FeC10). There is a wide variety of donor atoms (ligands) (O+NL, N+CL, NL, CO, CN, CL, Cl, SL, PL, I), which build up the respective inner coordination spheres about the metal atoms. The 17 complexes contain two crystallographically independent molecules within the same crystal, and 1 complex contains four such molecules. In each complex, the respective molecules are differing mostly by the degree of distortion in metal-metal and metal-ligand bond distances and ligand-metal-ligand bond angles, and are examples of distortion isomerism.

Structural aspects of heterotetranuclear platinum clusters-distortion isomers

Abstract This review includes 16 examples of distortion isomers of heterotetranuclear platinum clusters. The clusters are of the compositions: Pt3Sn, Pt2M2 (M=Au, Ag, W, Mo), and PtM3 (M=Os, Ru, Re). The four metal atoms are found in a distorted tetrahedral core (most common), planar-rhombohedral, spiked-triangular, and eight-membered ring skeleton. There are three pairs (Pt2W2, Pt2Au2, and Pt2Ag2) of clusters and all remainder clusters contain two crystallographically independent molecules within the same crystal. All are classical examples of distortion isomerism. Their structures are analyzed and discussed.

Distortion isomers of PtM, Pt2M, PtM2 and PtMM′ (M = non-transition metals) derivatives-structural aspects

Abstract An analysis of the structural parameters of PtM, Pt2M, PtM2 and PtMM′ (M = non-transition metals) derivatives shows that each complex contains two crystallographically independent molecules within the same crystal. The respective molecules differ by the degrees of distortion and exemplify the distortion isomerism. These are discussed in terms of the coordination with the platinum and the M atoms and the correlations are drawn among the metal atoms, donor atoms, bond lengths and bond angles. A wide variety of non-transition metals (Sn, Ga, In, Tl, Zn, Cd, Hg, Sb) exist, among which the most prevalent is Sn.

Organophosphines in organoplatinum complexes: structural aspects of trans-PtP2C2 derivatives

AbstractThis review summarized and analyzed the structural parameters of 174 monomeric organoplatinum complexes with an inner coordination sphere of trans-PtP2C2. These complexes crystallized in four crystal systems: hexagonal (x2), orthorhombic (x13), triclinic (x76), and monoclinic (x84). These complexes, on the basis of the coordination mode of the respective donor ligands, can be divided into the seven sub-groups: Pt(PL)2(CL)2, Pt(PL)2(η2-C2L), Pt(η2-P2L)(CL)2, Pt(PL)(η2-P,CL)(CL), Pt(η2-P,CL)2, Pt(η3-P,C,PL)(CL), and Pt(η3-C,P,CL)(PL). The chelating ligands create 4-, 5-, 6-, 16-, 17-, 18-, and 19-membered rings. The total mean values of Pt-L bond distances are 2.055 Å (C) and 2.300 Å (P). There are examples that exist in two isomeric forms and are examples of distortion isomerism. The structural parameters of trans-PtP2C2 are discussed with those of cis-PtP2C2 derivatives.

THIO-LIGANDS in MONOMERIC Pt(II) COMPLEXES – STRUCTURAL ASPECTS

This review includes over three hundred derivatives in which each Pt(II) atom is in a distorted square planar environment with inner coordination spheres of PtS4, PtS3X, PtS2X2, PtSX3, PtS2XY, PtSX2Y and PtSXYZ. There is a wide variety of mono-, bi- , ter- , and tetra-dentate ligands, all incorporating both homo- and hetero-dentate varieties. The most common ligands are dimethylsulphoxide and triphenylphosphine. The chelating ligands create a wide variety of metallocyclic rings, where the effects of both steric and electronic factors are observed. Examples of cis– and trans– isomerism exists in these derivatives as well as distortion isomerism, which is much more common. Ligands exerting the trans– effect in these Pt(II) complexes are stronger in the order: OL, NL < Cl < Br < I < SL < H ~ AsL ~ PL ~ CN. Several relationships between the structural parameters were found and are discussed. The complexes crystallized in five crystal classes: hexagonal (0.4%) < tetragonal (1.5%) < orthorhombic (13.8%) < triclinic (23.7%) < monoclinic (60.7%).

ChemInform Abstract: Organophosphines in Organoplatinum Complexes ‐ Structural Aspects of Trans‐PtP2CCl Derivatives

AbstractReview: 111 refs.

Stereoisomers of platinum dimeric and oligomeric coordination complexes

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.

Crystallographic and structural characterization of heterometallic platinum clusters. Part IX. Heterooligonuclear Pt clusters

Abstract This review classifies and analyzes over thirty heterooligonuclear platinum clusters with a wide variety of metal frameworks, from twelve to forty-four. There are thirteen heterometals (Ge, Sn, Hg, W, Mo, Ru, Rh, Pd, Os, Ni, Cu, Ag, Au) which are the partners of platinum. The clusters mostly crystallize in monoclinic (36,4%) and triclinic (30,3%) crystal classes. Their structures are complex, with platinum most commonly preferring interstitial sites, such as the centroids of icosahedrons. There are examples of distortion isomerism. The most common ligands are CO and PPh3, and it is interesting that the mean Pt-CO and M-CO bond distances are identical at 1.84 Å. In contrast, the mean Pt-μCO and M-μCO are of values of 2.02 and 1.97 Å, respectively, while the Pt-PPh3 and M-PPh3 bond distances are 2.30 and 2.28 Å, respectively. The shortest Pt-Pt, Pt-M (non-transition) and Pt-M (transition) bond distances are 2.559(2) Å, 2.412(2) Å (M = Ge) and 2.510(2) Å (M = Ni).

Structural Characterization of Heterometallic Gold – Iron Clusters

Structural survey of the clusters in Cambridge Structural Database was carried out to investigate the stereochemistry about gold and iron in their heterometallic clusters. Clusters ranging from heterobinuclear to polynuclear clusters were included in the survey. The gold atoms are surrounded from two to six donor atoms, and the iron atoms from six to ten donor atoms. The shortest Au-Fe, Fe-Fe and Au-Au bond distances are 2.438(3), 2.504(3) and 2.630(1)A. There are few clusters, which contain two crystallographically independent molecules and another one which contains four such molecules. Those are classical examples of distortion isomerism. Correlations between structural parameters and donor atoms are given.

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

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)&lt;270.5 pm (tetramers)&lt;271.5 pm (dimers)&lt;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.

Crystallographic and structural characterization of heterometallic platinum clusters Part VIII. Heteronona- and heterodecanuclear clusters

Abstract This review classifies and analyses fifty heteronona- and heterodecanuclear Pt clusters of metal composition: Pt4Ru5, Pt3Ru6, Pt20sr PtRh8, PtAu8; Pt6M4, Pt5M5, Pt4M6, Pt3M2, Pt2M8, PtM9, Pt3Ru6M and PtAu8M. There are nine different heterometals: M = Ru, Au, Ag, Cu, Hg, Os, Rh, Ir and Fe, of which Ru and Au are the most frequent. The clusters crystallize mostly into two crystal classes, monoclinic (74%) and triclinic (18%), and their structures are complex. Three triangular layers of nine metal atoms arranged in the form of a face-shared bioctahedron are common in the series of heterononanuclear clusters. In the series of heterodecanuclear clusters distorted skeletal icosahedrons, where a central platinum atom is surrounded by nine metal atoms, and face (edge) shared (fused) bioctahedral cluster of the metal atoms are the most common. The most frequent ligands are CO and PPh3. The shortest metal-metal bond distances are: 2.540(4) Å (Pt-Fe), 2.580(2) Å (Ru-Ru), 2.584 Å (Pt-Pt) and 2.629(4) Å (Cu-Au). Several relationships between the structural parameters were found and are discussed. Some clusters contain two crystallographically independent molecules within the same crystal and are examples of distortion isomerism.

Crystallographic and structural characterization of heterometallic platinum complexes Part VI. Heterohexanuclear complexes

Abstract This review classifies and analyzes heterohexanuclear platinum clusters into seven types of metal combinations:Pt5M, Pt4M2, Pt3M3, Pt2M4, PtM5, Pt2M3M′, and Pt2M2M2′. The crystals of these clusters generally belong to six crystal classes: monoclinic, triclinic, orthorhombic, tetragonal, trigonal and cubic. Among the wide range of stereochemistry adopted by these clusters, octahedral and capped square-pyramidal are the most common. Although platinum is classified as a soft metal atom, it bonds to a variety of soft, borderline and hard metals. Nineteen different heterometal ions are involved in hexanuclear platinum clusters. The shortest Pt-M bond distance in the case of M being a non-transition element is 2.395(4) Å for germanium and for M being a transition metal ion it is 2.402(2) Å for Cobalt. The shortest Pt-Pt bond distance observed in these clusters is 2.532 Å. Several relationships between the structural parameters are identified and discussed. Some clusters exist in two isomeric forms and some show crystallographically independent molecules within the same crystal. Such isomers and independent molecules are examples of distortion isomerism.

Distortional Supramolecular Isomers of Polyrotaxane Coordination Polymers: Photoreactivity and Sensing of Nitro Compounds

AbstractDistortional isomers, or bond‐stretch isomers, differ only in the length of one or more bonds, which is due to crystallographic disorder in most cases. The term distortional isomerism is introduced to describe the structures of polyrotaxane 2D coordination polymers (CPs) that differ only by the relative positions in the neighboring entangled axles. A large ring and a long spacer ligand in 2D CPs yielded four different supramolecular isomers, of which two have an entangled polyrotaxane structure. One pair of CC bonds in the spacer ligand is well‐aligned in one isomer and undergoes [2+2] cycloaddition reaction, whereas the other isomer is photoinert. They also have different sensing efficiency for several aromatic nitro compounds. However, both isomers show selective PL quenching for the Brady’s reagent. Structurally similar supramolecular isomers with different photochemical reactivity and sensing abilities appear to be unprecedented.

Crystallographic and structural characterization of heterometallic platinum complexes Part V. Heteropentanuclear complexes

Abstract This review classifies and analyzes over eighty heteropentanuclear Pt complexes. There are eight types of metal combinations: Pt4M, Pt3M2, Pt2M3, PtM4, Pt3MM′, Pt2M2M′, PtM2M′2 and PtM3M′. The five metal atoms are in a wide variety of arrangements: trigonal-bipyramidal (most common), square-pyramidal, spike-triangular, butterfly, cubane, linear and one unique. Platinum bonds to a variety of triad partner metal atoms, soft, through borderline to hard. The shortest Pt-M bond distances for non-transition and transition M are 2.406(4) Å (M = Ge) and 2.30(1) Å (M = Co). The shortest Pt-Pt bond distance is 2.580(1) Å. Several relationships between the structural parameters were found and are discussed. Several complexes exist in two isomeric forms and others contain two crystallographically independent molecules. Both the isomers as well as independent molecules are examples of distortion isomerism.