Dithiolene complex adducts. Crystal and molecular structure of tetrapropylammonium bis(maleonitriledithiolato)-1,10-phenanthrolinecobaltate, [(n-C3H7)4N] [Co(S2C2(CN)2)2(o-phen)]

Khare, G. P.; Eisenberg, Richard

doi:10.1021/ic50092a003

Cited by 18 publications

(6 citation statements)

References 9 publications

(12 reference statements)

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“…Frenz & Ibers (1972) have noted that there is a correlation between the metal-nitrogen bond distance and the angle subtended by the nitrogen atoms at the metal since the N...N separation in phenanthroline is inflexible. In two recently reported Co(Ill) complexes the bites of the phenanthroline ligands were 2.72 (2) A and 2.63 (3) A (Khare & Eisenberg, 1970;Pierpont & Eisenberg, 1970), in Ni(,phen)a 2÷ it is 2"66 (1) A and in the present case it is 2.621 (7) A; these four values do not appear to differ significantly, which is consistent with this concept. Table 5.…”

Section: :"~ " '; I I~!i Il Ii Il I!! I! I! Ii I Ii Ii I! I I:~i Isupporting

confidence: 90%

“…There are clearly significant deviations from planarity in some of the rings, especially in phen 4, but we are unable to discern any significant trend. This non-planarity of phenanthroline groups has also been observed by several other workers (Graham & Fenn, 1970;Preston & Kennard, 1969a, b;Pierpont & Eisenberg, 1970;Khare & Eisenberg, 1970;Frenz & Ibers, 1972). The chromium atoms do not lie in these least-squares planes; thus Cr(1) is 0.07 and 0-28 A out of the planes through phen 1 and phen 3, respectively, while Cr (2) is 0.28 and 0.18 A from those through phen 2 and phen 4, respectively.…”

Section: :"~ " '; I I~!i Il Ii Il I!! I! I! Ii I Ii Ii I! I I:~i Isupporting

confidence: 86%

“…The Cr-N distances also correlate well with the Ni(II)-N and Co(III)-N lengths in Ni(phen) 2+ (Frenz & Ibers, 1972) and [Co(SzC2(CN)z)z-(phen)]- (Khare & Eisenberg, 1970). The average Ni-N distance in Ni(phen) 2+ is 2.090 (5) A, or 0.038 A longer than the average Cr-N value here, while the average Co-N distance is 2.009 (12) A., or 0.043 A shorter than our Cr-N distance; this observed order of the M-N distances is that predicted from the covalent radii of the metal atoms (Pauling, 1960).…”

Section: :"~ " '; I I~!i Il Ii Il I!! I! I! Ii I Ii Ii I! I I:~i Imentioning

confidence: 65%

“…HATFIELD AND DEREK J. HODGSON 19 cases of Ni(phen)~ + (Frenz & Ibers, 1972) and (Khare, Pierpont & Eisenberg, 1968;Khare & Eisenberg, 1970), the average values of the C-C and C-N bonds in the phenanthroline rings correlate quite well with Pauling's n bond orders; thus, for example, the longest C-C bonds are C(5)-C(13), C(6)-C(14) and C(11)-C(12), which have only ½ double-bond character, while the shortest C-C bond is C(5)-C(6), which has -} double-bond character. Frenz & Ibers (1972) have noted that there is a correlation between the metal-nitrogen bond distance and the angle subtended by the nitrogen atoms at the metal since the N...N separation in phenanthroline is inflexible.…”

Section: :"~ " '; I I~!i Il Ii Il I!! I! I! Ii I Ii Ii I! I I:~i Imentioning

confidence: 99%

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The crystal and molecular structure of di-μ-hydroxobis[di(1,10-phenanthroline)chromium(III)] chloride hexahydrate

Veal¹,

Hatfield²,

Hodgson³

1973

Acta Crystallogr Sect B

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THE STRUCTURES OF FLUORIDES. Iresult of decreasing stability of the octahedral structure with decreasing cation size, with a consequent tendency to form fivefold and, finally, tetrahedral coordination. In the alkali metal niobates (Megaw, 1968b) The Crystal and Molecular Structure of Di-~t-hydroxobisldi(1,10-phenanthroline)chromium(III)l Chloride Hexahydrate BY JACK T. VEAL,* WILLIAM E. HATFIELD AND DEREK J. HODGSONt Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27514, U.S.A. (Received 17 May 1972; accepted 14 September 1972)The crystal and molecular structure of di-/t-hydroxobis[di(1,10-phenanthroline)chromium(IlI)] chloride hexahydrate, [Cr(phen)2OH]2Cla.6H20, has been determined from three-dimensional counter X-ray data. The material crystallizes in the triclinic space group PI with two dimeric formula units in a cell whose dimensions are a= 14.056 (7), b= 11.296 (6), c= 18.990 (9) A, ~=87.15 (3), fl= 107-63 (2), and ),=74.68 (3) °. The observed and calculated densities are 1.39 (4) and 1.342 g cm -3 respectively. The structure has been refined by full-matrix least-squares techniques to a conventional R value of 0.077 for 3392 independent intensities greater than three times their estimated standard deviations. The complex consists of pairs of chromium atoms which are linked by two hydroxo bridges, with two 1,10-phenanthroline groups coordinated to each metal; the coordination geometry around each chromium is roughly octahedral. The average Cr-N and Cr-O bond lengths are 2-052 (6) and 1.927 (6) .~, respectively, while the Cr-Cr separation is 3.008 (3) ,& and the average Cr-O-Cr angle is 102-7 (4) °. The geometry of this complex is compared with that of [Cr(gly)2OH]2 and with those of complexes of the type [CuLOH]~. +, and the magnetic properties of the complex are discussed in terms of the bridging geometry.

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Section: :"~ " '; I I~!i Il Ii Il I!! I! I! Ii I Ii Ii I! I I:~i Isupporting

confidence: 90%

Section: :"~ " '; I I~!i Il Ii Il I!! I! I! Ii I Ii Ii I! I I:~i Isupporting

confidence: 86%

Section: :"~ " '; I I~!i Il Ii Il I!! I! I! Ii I Ii Ii I! I I:~i Imentioning

confidence: 65%

Section: :"~ " '; I I~!i Il Ii Il I!! I! I! Ii I Ii Ii I! I I:~i Imentioning

confidence: 99%

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The crystal and molecular structure of di-μ-hydroxobis[di(1,10-phenanthroline)chromium(III)] chloride hexahydrate

Veal¹,

Hatfield²,

Hodgson³

1973

Acta Crystallogr Sect B

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“…The redox potential of cytochrome c is independent of ionic strength around 0.1 M at neutral pH, with a value of 260 mV (13). The properties of the four reagents (14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24) to be discussed in detail are given in Table 1.…”

Section: Theorymentioning

confidence: 99%

Metalloprotein electron transfer reactions: analysis of reactivity of horse heart cytochrome c with inorganic complexes.

Wherland¹,

Gray²

1976

Proc. Natl. Acad. Sci. U.S.A.

115

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The reactions of horse heart cytochrome c with Fe(ethylenediaminetetraacetate)r, Co(1, It has been suggested previously that electron transfer between horse heart cytochrome c and certain inorganic redox agents takes place by an outer-sphere mechanism at the heme edge that is partially exposed at the protein surface (1-3). In a particularly striking example, the calculated protein self-exchange rate constant (k1) based on oxidation of ferrocytochrome c by Co(phen)33+ (phen = 1,10-phenanthroline) has been shown to be in good agreement with the measured value, suggesting that the crossreaction involves a very similar mechanism (2). It should not necessarily be expected, however, that all reagents will have equal access to the heme edge in solution, as examination of structural models reveals that hydrophobic residues surround it. Indeed, the degree of access to the heme edge needs to be determined for a variety of substrates of various sizes, charges, and surface properties.The purpose of this paper is to present a detailed analysis of the kinetics of the electron transfer reactions of cytochrome c with Fe(CN)O3, Ru(NH3)(j+, Co(phen)33+, and Fe(EDTA)2-(EDTA = ethylenediaminetetraacetate). We shall employ the Marcus theory of outer-sphere electron transfer reactions to compensate for the variation in driving force and inherent reactivity of the reagents. Special attention will be directed to the evaluation of the electrostatic interactions between the protein and each reagent, thereby allowing an estimate to be made of the magnitudes of nonelectrostatic contributions to the activation free energies for the reactions. THEORYThe Marcus theory correlates the crossreaction rate constant (k12) with the electron exchange rate constants for the two reactants (kil and k22) and the equilibrium constant (K) through the expressions k12 = (klk22Kf)/2 [1] phen, 1,10-log f = (log K)2/[4 log (kilk22/Z2)] [2] where the factor f is quite near 1 for the reactions to be considered here because they have rather small equilibrium constants (Z is the collision frequency) (4). With the inclusion of adiabaticity factors p, Eq. 1 becomes k12 = pI2(k11k22Kf/ p1Ip22)/2 (4). For the purposes of this treatment, it will be assumed that the reactions are adiabatic (Plu = P22 = P12 = 1), or at least uniformly nonadiabatic (p122 = PlIP22). Eq. 1 may.be applied as written, and the predicted kl2 value may be calculated from known values of ki1, k22, and K. In this approach, any deviation of the calculated from the observed values can be attributed to either the protein's or the reagent's undergoing a different activation process than in the self-exchange reaction, or to interaction energies between the reagent and protein which are not cancelled by the interactions in the exchange processes. Alternatively, it may be assumed that the activation process for reagent electron transfer, characterized by the exchange rate k22, is approximately a constant. Under this assumption Eq. 1 can be solved for kI, (the subscript 1 refers to the protein in ...

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ChemInform Abstract: DITHIOLEN‐KOMPLEXADDUKTE, KRISTALL‐ UND MOLEKULARSTRUKTUR VON TETRA‐N‐PROPYLAMMONIUM‐BIS‐(MALEONITRILDITHIOLATO)‐1,10‐PHENANTHROLINCOBALTAT UND TETRA‐N‐BUTYLAMMONIUM‐BIS‐(TOLUOL‐3,4‐DITHIOLATO)‐1,10‐PHENANTHROLINCOBALTAT

Khare¹,

Eisenberg²

1970

Chemischer Informationsdienst. Organische Chemie

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Dithiolene complex adducts. Crystal and molecular structure of tetrapropylammonium bis(maleonitriledithiolato)-1,10-phenanthrolinecobaltate, [(n-C3H7)4N] [Co(S2C2(CN)2)2(o-phen)]

Cited by 18 publications

References 9 publications

The crystal and molecular structure of di-μ-hydroxobis[di(1,10-phenanthroline)chromium(III)] chloride hexahydrate

The crystal and molecular structure of di-μ-hydroxobis[di(1,10-phenanthroline)chromium(III)] chloride hexahydrate

Metalloprotein electron transfer reactions: analysis of reactivity of horse heart cytochrome c with inorganic complexes.

ChemInform Abstract: DITHIOLEN‐KOMPLEXADDUKTE, KRISTALL‐ UND MOLEKULARSTRUKTUR VON TETRA‐N‐PROPYLAMMONIUM‐BIS‐(MALEONITRILDITHIOLATO)‐1,10‐PHENANTHROLINCOBALTAT UND TETRA‐N‐BUTYLAMMONIUM‐BIS‐(TOLUOL‐3,4‐DITHIOLATO)‐1,10‐PHENANTHROLINCOBALTAT

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