Structural studies on clathro chelate complexes. IV. 1,3 Trigonal-prismatic coordination of d10zinc(II) in crystalline [fluoroborotis(2-aldoximo-6-pyridyl)phosphine]zinc(II) tetrafluoroborate

Reis, Arthur H.

doi:10.1021/ic50128a014

Cited by 18 publications

(5 citation statements)

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“…It is noteworthy that the M−N ox bond lengths are shorter than the M−N py bond distances: 0.02 Å for Mn II ( 2 ); 0.06 Å for Fe II ( 3 ), Ni II ( 4 ), and Co III ( 7 ); 0.01 Å for Ni II ( 8 ). A similar trend was also found for BF-capped mononuclear complexes with the PyA ligand. , The average M−N py and M−N ox bond lengths fall within the ranges that are considered as normal covalent bonds for M(II) or Co(III) centers with a high-spin configuration for Mn(II) (d 5 ) ( 2 ) and Ni(II) (d 8 ) ( 4 , 8 ) and a d 6 low-spin electronic configuration for Fe(II) ( 3 ) and Co(III) ( 7 ).…”

Section: Resultssupporting

confidence: 75%

Tris(pyridinealdoximato)metal Complexes as Ligands for the Synthesis of Asymmetric Heterodinuclear Cr^IIIM Species [M = Zn(II), Cu(II), Ni(II), Fe(II), Mn(II), Cr(II), Co(III)]: A Magneto−Structural Study

et al. 2001

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Reactions of the LCr(III) unit with an in situ prepared M(PyA)(3)(n-) ion, where L represents 1,4,7-trimethyl-1,4,7-triazacyclononane and PyA(-) is the monoanion of pyridine-2-aldoxime, yield heterodinuclear complexes of general formula [LCr(III)(PyA)(3)M](2+/3+) as perchlorate salts, where M = Cr(II) (1), Mn(II) (2), low-spin Fe(II) (3), Ni(II) (4), Cu(II) (5), Zn(II) (6), and low-spin Co(III) (7). These compounds contain three oximato anions as bridging ligands. The hexadentate ligand with the identical donor atoms, tris(2-aldoximato-6-pyridyl)phosphine, P(PyA)(3), has been employed to prepare a second Cr(III)Ni(II) species 8, whose magnetic properties differ significantly from those of 4. Complexes 1-8 have been characterized on the basis of elemental analysis, mass spectrometry, IR, UV-vis, Mössbauer, and EPR spectroscopies, and variable-temperature (2-295 K) magnetic susceptibility measurements. They are isostructural in the sense that they all contain a terminal Cr(III) ion in a distorted octahedral environment, CrN(3)O(3), and a second six-coordinated metal ion M in a mostly trigonal prismatic MN(6) geometry. The crystal structures of the perchlorate salts of 2-5, 7, and 8 have been determined by X-ray crystallography at 100 K. The structures consist of mixed-metal Cr(III)M(II) and Cr(III)Co(III) complexes with a geometry in which two pseudooctahedral polyhedra are joined by three oximato (=N-O(-)) groups, with an intramolecular Cr.M(Co) distance in the range of 3.4-3.7 A. The cyclic voltammograms of the complexes reveal ligand oxidation and reduction processes, and in addition, metal-centered oxidation processes have been observed. X-band EPR spectroscopy has been used to establish the electronic ground state of the heterodinuclear complexes. Analysis of the susceptibility data indicates the presence of weak exchange interactions, both ferro- and antiferromagnetic, between the paramagnetic centers. A qualitative rationale on the basis of the Goodenough-Kanamori rules is provided for the difference in magnetic behaviors.

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Section: Resultssupporting

confidence: 75%

Tris(pyridinealdoximato)metal Complexes as Ligands for the Synthesis of Asymmetric Heterodinuclear Cr^IIIM Species [M = Zn(II), Cu(II), Ni(II), Fe(II), Mn(II), Cr(II), Co(III)]: A Magneto−Structural Study

et al. 2001

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“…Figure1, the phenyl rings, including the hydrogens, were treated as rigid bodies. The resulting geometry is in good agreement with other determinations14'28-29 of this cation with average As-C bond distance, TableIV, being 1.889(7) Á while…”

supporting

confidence: 89%

“…, S(3), C(7), C(8), C(9), S(10), S(ll), S(12) 17.6 Ta, S(4), S(5) S(4), S(5), C( 13), C(14), C(15), C(16), C(17), C(18) 30.0 S(l), S(3), S(5) S(2), S(4), S(6…”

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Crystal and molecular structure of tetraphenylarsonium tris(benzenedithiolato)tantalate(V)

Martin¹,

Takats²

1975

Inorg. Chem.

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The crystal and molecular structure of tetraphenylarsonium tris(benzenedithiolato)tantalate(V), [(CsHs^As] [Ta(S2C6Ü4)3], has been determined from three-dimensional X-ray diffraction methods using data collected with an automated diffractometer.The compound crystallizes in the triclinic space group P\ (No. 1) with one molecule per unit cell of dimensions a = 9.442 (1), b = 9.752 (1), c = 11.872 (2) A and a = 77.37 (1), ß = 71.20 (1), y = 74.23 (1)°. The observed and calculated densities are 1.67 (2) and 1.66 g cm™3, respectively. A total of 3700 reflections with 2 < 50°were collected; of these, 3532 with Zobsd > 3 ( ) were used in the structure derivation giving final conventional values of R = 0.027 and Z?w = 0.031 (the number of parameters refined in the last full-matrix least-squares cycle was 280). The coordination geometry of the Ta is severely distorted from the trigonal-prismatic geometry observed in the corresponding Nb structure, in accord with our expectations based on spectral differences. The average Ta-S bond length, 2.43 (1) A, is very similar to the one found in Nb. The distortion is quite unique with two of the chelate rings being close to the prismatic limit while the third one is twisted about the twofold axis of the prism to the octahedral extreme; the individual twist angles are 16, 16, and 54°. As a result, the two triangular faces are no longer parallel but inclined by 12°. The relevance of the observed distortion to the factors affecting the trigonal-prismatic geometry is discussed.

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“…Bridging this theoretical gap are the well-compiled Shannon−Prewitt tables, , which give ionic radii of transition metals (and nonmetals) as a function of charge and coordination number. Though these values were collected from essentially ionic materials, the Shannon−Prewitt tables have nonetheless proved useful in analysis of discrete molecular compounds. , Inspection of the these tables reveals trends which are consistent for a variety of metals, as shown in Table .…”

Section: Introductionmentioning

confidence: 99%

Metal−Ligand Bond Distances in First-Row Transition Metal Coordination Compounds: Coordination Number, Oxidation State, and Specific Ligand Effects

1998

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Mean metal−ligand bond distances for the coordination ligands isothiocyanate, pyridine, imidazole, water, and chloride, bound to the transition metals Mn, Fe, Co, Ni, Cu, and Zn in their 2+ oxidation states, were collected from searches the Cambridge Structure Database. The metal−ligand bond distances were converted to bond orders through the bond distance-bond order technique, as suggested by Pauling. The mean bond order sums at the 2+ metal centers were found to be independent of coordination number or geometry and to be strongly ligand-dependent; the values (by ligand) are as follows: isothiocyanate = 2.56 ± 0.13; imidazole = 2.13 ± 0.04; chloride = 2.12 ± 0.07; pyridine 1.95 ± 0.10; water = 1.88 ± 0.10. The bond order sum for Fe(III) bound to chloride was found to be 3.09, approximately one bond order unit larger than for the 2+ metal centers bound to chloride. Division of the ligand-specific bond order sums by coordination number allows prediction of the M−L bond distance to within 0.017 Å, regardless of the specific coordination geometry. The physical basis for the ligand-specific variation in bond order sum is also discussed.

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Structural studies on clathro chelate complexes. IV. 1,3 Trigonal-prismatic coordination of d10zinc(II) in crystalline [fluoroborotis(2-aldoximo-6-pyridyl)phosphine]zinc(II) tetrafluoroborate

Cited by 18 publications

References 4 publications

Tris(pyridinealdoximato)metal Complexes as Ligands for the Synthesis of Asymmetric Heterodinuclear Cr^IIIM Species [M = Zn(II), Cu(II), Ni(II), Fe(II), Mn(II), Cr(II), Co(III)]: A Magneto−Structural Study

Tris(pyridinealdoximato)metal Complexes as Ligands for the Synthesis of Asymmetric Heterodinuclear Cr^IIIM Species [M = Zn(II), Cu(II), Ni(II), Fe(II), Mn(II), Cr(II), Co(III)]: A Magneto−Structural Study

Crystal and molecular structure of tetraphenylarsonium tris(benzenedithiolato)tantalate(V)

Metal−Ligand Bond Distances in First-Row Transition Metal Coordination Compounds: Coordination Number, Oxidation State, and Specific Ligand Effects

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Structural studies on clathro chelate complexes. IV. 1,3 Trigonal-prismatic coordination of d10zinc(II) in crystalline [fluoroborotis(2-aldoximo-6-pyridyl)phosphine]zinc(II) tetrafluoroborate

Cited by 18 publications

References 4 publications

Tris(pyridinealdoximato)metal Complexes as Ligands for the Synthesis of Asymmetric Heterodinuclear CrIIIM Species [M = Zn(II), Cu(II), Ni(II), Fe(II), Mn(II), Cr(II), Co(III)]: A Magneto−Structural Study

Tris(pyridinealdoximato)metal Complexes as Ligands for the Synthesis of Asymmetric Heterodinuclear CrIIIM Species [M = Zn(II), Cu(II), Ni(II), Fe(II), Mn(II), Cr(II), Co(III)]: A Magneto−Structural Study

Crystal and molecular structure of tetraphenylarsonium tris(benzenedithiolato)tantalate(V)

Metal−Ligand Bond Distances in First-Row Transition Metal Coordination Compounds: Coordination Number, Oxidation State, and Specific Ligand Effects

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Product

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Tris(pyridinealdoximato)metal Complexes as Ligands for the Synthesis of Asymmetric Heterodinuclear Cr^IIIM Species [M = Zn(II), Cu(II), Ni(II), Fe(II), Mn(II), Cr(II), Co(III)]: A Magneto−Structural Study

Tris(pyridinealdoximato)metal Complexes as Ligands for the Synthesis of Asymmetric Heterodinuclear Cr^IIIM Species [M = Zn(II), Cu(II), Ni(II), Fe(II), Mn(II), Cr(II), Co(III)]: A Magneto−Structural Study