Shape maps and polyhedral interconversion paths in transition metal chemistry

Álvarez, Santiago; Alemany, Pere; Casanova, David; Cirera, Jordi; Llunell, Miquel; Avnir, David

doi:10.1016/j.ccr.2005.03.031

Cited by 956 publications

(719 citation statements)

References 25 publications

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“…All the hydrogen atoms, connected to the aromatic rings (C-H 55 0.95Ǻ) were fixed geometrically and were refined using a riding model with common isotropic displacements. Compound 2 was solved in the tetragonal I 4 1 /a space group with Superflip 54 program, which allowed us to obtain the position of Co atoms, as well as nitrogen and some of the carbon atoms of 60 the TPPS and bipyridine molecules. The refinement of the crystal structure was performed by full matrix least-squares based on F 2 , using the SHELXL-97 program 53 obtaining the remaining carbon atoms and the oxygen and sulphur atoms of the porphyrin and water molecules.…”

Section: Single-crystal X-ray Diffractionmentioning

confidence: 99%

“…43,44 Thus, the work herein presented consists of the synthesis and characterisation of two new CoP-bipy compounds where the metal ion is Co II and P is TPP for compound 1, and TPPS for compound 2. Both of them have been structurally characterised 60 by single-crystal X-ray diffraction (XRD) and IR and EPR spectroscopies. Thermal stability has been explored by means of thermogravimetry (TGA), and X-ray thermodiffractometry (TDX).…”

Section: Introductionmentioning

confidence: 99%

“…61,62 For compound 1 the results indicate a ruffle-type distortion (ruf, B 1u ) for the coordinated porphyrin, and a slight wavy one 60 (wav(y), [E g(y) ]) for the crystallisation complex. The contribution of the ruffled porphyrin (1.4813) to the total displacements is 82.5%, while the wavy porphyrin shows a principal contribution of wav(y) (-0.1910) mixed with a small amount of the wav(x) (0.0884) deformation.…”

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confidence: 98%

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Thermal stability and crystallochemical analysis for CoII-based coordination polymers with TPP and TPPS porphyrins

et al. 2013

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Two new CoP-bipy compounds have been synthesised and characterised, where P is TPP for compound 1 (TPP= meso-tetraphenylporphyrin) and TPPS for compound 2 (TPPS= meso-tetraphenylporphinetetrasulfonic acid tetrasodium salt), and bipy is 4,4´-bipyridine. Compound 1 consists of 1D polymers packed in a network where isolated porphyrin units are immobilized by an extended π-bond system. On 10 the other hand, as we are aware, compound 2 is the first Co-TPPS compound in literature. It also consists of 1D polymers that are formed by the alternation of two distinct metal centres. These unprecedented polymers are packed forming cavities where crystallization molecules of water are located. The robustness of the hydrogen bond system and a topology based on interpenetrated nets are responsible for the high thermal stability of compound 2. Additionally, a crystallochemical study confirmed the existence 15 of a correlation between the degree of ruffled distortion of the porphyrin macrocycle and some selected dihedral angles and distances for Co II porphyrins in literature.

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Section: Single-crystal X-ray Diffractionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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confidence: 98%

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Thermal stability and crystallochemical analysis for CoII-based coordination polymers with TPP and TPPS porphyrins

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“…In the literature on the lanthanide contraction to date, however, terms like "isostructural" and 'isotypical" have been used in a rather qualitative fashion, although there have been some efforts to develop a more quantitative measure for the similarity of coordination compounds. 11 For the investigation of the present series of lanthanide complexes, a shape measure approach was utilized based on the dihedral angles along the edges of the coordination polyhedron. 12 As the reference polyhedron the gadolinium complex was chosen due to the central position within the lanthanide series.…”

Section: Isostructuralmentioning

confidence: 99%

The Lanthanide Contraction Revisited

2007

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A complete, isostructural series of complexes with La-Lu (except Pm) with the ligand TREN-1,2-HOIQO has been synthesized and structurally characterized by means of single-crystal X-ray analysis. All complexes are 1D-polymeric species in the solid state, with the lanthanide being in an eight-coordinate, distorted trigonal-dodecahedral environment with a donor set of eight unique oxygen atoms. This series constitutes the first complete set of isostructural complexes from La-Lu (without Pm) with a ligand of denticity greater than two. The geometric arrangement of the chelating moieties slightly deviates across the lanthanide series, as analyzed by a shape parameter metric based on the comparison of the dihedral angles along all edges of the coordination polyhedron. The apparent lanthanide contraction in the individual Ln-O bond lengths deviates considerably from the expected quadratic decrease that was found previously in a number of complexes with ligands of low denticity. The sum of all bond lengths around the trivalent metal cation, however, is more regular, showing an almost ideal quadratic behavior across the entire series. The quadratic nature of the lanthanide contraction is derived theoretically from Slater's model for the calculation of ionic radii. In addition, the sum of all distances along the edges of the coordination polyhedron show exactly the same quadratic dependence as the Ln-X bond lengths. The universal validity of this coordination sphere contraction, concomitant with the quadratic decrease in Ln-X bond lengths, was confirmed by reexamination of four other, previously published series of lanthanide complexes. Due to the importance of multidentate ligands for the chelation of rare-earth metals, this result provides a significant advance for the prediction and rationalization of the geometric features of the corresponding lanthanide complexes, with great potential impact for all aspects of lanthanide coordination.

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“…Note that the oxidation of Mn II to Mn III occurs undoubtedly by the atmospheric O2 under the prevailing basic conditions [35,36]. The central lanthanide ion is eight-coordinate possessing a slightly distorted square antiprismatic geometry with a continuous shape measurement factor of CShM = 0.71 ( Figure S2) [37]. The closest this number is to zero, the closest is the geometry of the lanthanide to the ideal one.…”

Section: Introductionmentioning

confidence: 99%