The crystal structure of carbonatotetrakis(pyridine)cobalt(III) perchlorate monohydrate

Kaas, K.; Sorensen, Astrid

doi:10.1107/s0567740873002050

Cited by 13 publications

(6 citation statements)

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“…The carbonato group is planar but makes an angle of 4.3 ° with the plane formed by .,,,p Co, N(1) and N(3). The dimensions of the coordinated carbonato group closely resemble those of other cobalt--carbonato systems reported (Kaas & Sorensen, 1973;Geue & Snow, 1971;Barclay & Hoskins, 1962). The crystal is composed of discrete ions, linked by weak hydrogen bonds, which form a three-dimensional network.…”

Section: Cis-~-[co(co3)(38-dimetrien)] + Is Presented Inmentioning

confidence: 51%

The crystal structure of (+)589-cis-β-carbonato-(3S,8S-dimethyltriethylenetetramine)cobalt(III) perchlorate

Toriumi¹,

Saitō²

1975

Acta Crystallogr Sect B

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[Co(CO3) (3,8-dimetrien)]CIO4 crystallizes in the space group P2~2~2,, with four formula units in a cell of dimensions a= 12"284 (2), b= 17"913 (8) and c= 7.179 (3) A. The structure was solved by the heavyatom method and the positional and thermal parameters were refined by the method of least squares, using anisotropic thermal factors for the non-hydrogen atoms. The final R value for the 1894 observed reflexions collected by diffractometry is 0.041. The quadridentate ligand is linked to the central metal atom in cis-fl coordination. One of the substituted methyl groups lies in an equatorial position with respect to the chelate ring, while the other is in an axial position. All the bond lengths are normal. The Co-N distances range from 1"935 (5) to 1"958 (5) A. The absolute configuration of the complex ion can be designated as A(622). The absolute configurations about the two secondary nitrogen atoms are both R.

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Section: Cis-~-[co(co3)(38-dimetrien)] + Is Presented Inmentioning

confidence: 51%

The crystal structure of (+)589-cis-β-carbonato-(3S,8S-dimethyltriethylenetetramine)cobalt(III) perchlorate

Toriumi¹,

Saitō²

1975

Acta Crystallogr Sect B

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“…The uncoordinated phosphate oxygen O14 further shows H-bonding with the two water molecules O1W and O2W (2.781(5) and 2.681(4) A ˚, respectively) while the equivalent O(13) remains free. The chelate angle O(11)-Co-O(12) has a value of 76.43 (9) which is somewhat larger than the values of 68.8 17 and 69.3 18 found for the four-membered carbonato chelate rings and is comparable with the structurally similar complex [Co(en) 2 (PO) 4 ]. 16 As indicated in Fig.…”

mentioning

confidence: 65%

“…15,16 The Co-P distance is 2.5352( 9 The cobalt coordinated phosphate oxygen (O11, O12) distances are 4% longer than the uncoordinated phosphate oxygens (O13, O14). The two uncoordinated phosphate oxygens O(13) and O( 14) are at a distance of 1.523(3) and 1.503(3) A ˚, respectively, from the phosphorus, and all O-P-O angles other than the endocyclic one are slightly larger than the tetrahedral value, ranging between 97.21 (12) and 113.23 (18) . The uncoordinated phosphate oxygen O14 further shows H-bonding with the two water molecules O1W and O2W (2.781(5) and 2.681(4) A ˚, respectively) while the equivalent O(13) remains free.…”

mentioning

confidence: 99%

“…3. These cavities are 11)-Co-N(1B) 91.08 (13) N(1B)-Co-N(2A) 93.35( 14) O( 12)-Co-N(1B) 92.26 (12) N(1A)-Co-N(2A) 83.97( 14) O( 11)-Co-N(1A) 92.14 (12) N(1B)-Co-N(2B) 84.33( 14) O( 12)-Co-N(1A) 92.10( 12) N(1A)-Co-N(2B) 91.77( 14) O( 11)-Co-N(2A) 171.24 (13) N(2A)-Co-N(2B) 94.33( 12) O( 12)-Co-N(2A) 95.83 (13) O( 11)-Co-P 38.29( 10) O( 11)-Co-N(2B) 93.63 (15) O( 12)-Co-P 38.19( 9) O( 12)-Co-N(2B) 169.46 (14) N(1B)-Co-P 93.76( 8) O( 14)-P-O( 13) 113.23 (18) N(1A)-Co-P 91.06( 8) O( 14)-P-O( 12) 110.24 (18) N(2A)-Co-P 133.67( 10) O( 13)-P-O( 12) 110.4( 2) N(2B)-Co-P 131.92( 12) O( 14)-P-O(11) 111.69 (18) O( 14)-P-Co 125.11( 14) O( 13 The single-crystal X-ray structural analysis shows that the guest water molecules are anchored in the cavities via the formation of H-bonds to the surrounding supramolecular units. This observation prompted us to investigate the behaviour of the water molecules upon heating.…”

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confidence: 99%

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Hydrogen bond directed open-framework of bis(bipyridine-glycoluril) phosphatocobalt(III) with solvent accessible void space

2008

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The self-assembled secondary building unit [Co(BPG) 2 (PO 4 )]$2H 2 O (1) with peripheral urea fused tectons having inherent hydrogen bond acceptor (O atoms) and donor (N-H atoms) groups results in a three-dimensional open-framework architecture with approximately 35% of solvent-accessible void space.The two major types of interactions employed by chemists to engineer supramolecules with predefined dimensions (1D, 2D, or 3D), are metal-ligand bonding and hydrogen bonding. The metallosupramolecules thus generated have attracted attention in recent years due to their applications in diverse areas such as catalysis, optoelectronics, gas storage, ion exchange, molecular recognition and magnetism. 1-6 A commonly used strategy in building such extended network structures is to employ appropriate bridging ligands, which on complexation with metal ions form ''supramolecular glue'' resulting in polymer networks with channels, voids and porous structures encapsulating solvent molecules. 7 In this regard the study of metal phosphate architectures have been carried out in great detail especially to develop the channel structures mimicking natural zeolites that are made up of phosphate-mediated networks. 8,9 In this respect, hydrothermal/solvothermal synthesis using metal ions and multifuctional organic ligands is the most popular method, however limited control on the structure formation is achieved.The use of secondary building units as vertices has proven to be beneficial, which depends 10 on several factors such as inherent stereoelectronic properties of the ligand complemented by the metal stereochemical preferences which are further enhanced by the external conditions such as solvent, template, concentration, temperature, counteranion, etc. Thus the secondary building block can be judiciously modified by introducing suitable supramolecular synthons so as to achieve desired control and robustness in the structure. One such a supramolecular synthon is 2,2'-biimidazole and 2,2'-bibenzimidazole which can exhibit various coordination modes and further assemble into higher dimensional structures via hydrogen bonds and Cl-p intercations. 11 As part of our research program, we have exploited the use of a potentially good H-bonding and self-complimentary motif bipyridine-glycoluril (BPG) which is capable of coordinating with metal ions to generate self-assembled supramolecular synthons by conventional synthetic methods. 12 In our recent report we have shown that the sequential variation of the bipyridine-glycoluril ligand in mixed polypyridyl ruthenium(II) complexes results in the formation of diverse self-assembled supramolecular networks forming channels encapsulating water, solvent and anion molecules. 12 2-D assemblies forming the propeller-like [Fe II (BPG) 3 ] complex which self-assembles through H-bonding to a nanoporous network was reported by J. M. Lehn et al. 13 Concurrent with our interest in the supramolecular synthons of bipyridine-glycoluril, and to explore the variation in the structure formed when one of the poly...

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“…The distance 4.5 A is substantially greater than the inner sphere coordination distance expected from structural studies of Co(II) complexes, which is 2.9-3.0 A for acetate-type monodentate binding or 2.5 A for carbonate bidentate binding (24)(25)(26). Neither is as long as the distance expected for outer sphere coordination, which is 5.1-5.7 A (27,28). Rather, it suggests a contribution from bound inner and outer sphere HCO3-ions.…”

Section: Methodsmentioning

confidence: 80%

13-C nuclear magnetic resonance studies on the mechanism of action of carbonic anhydrase.

Yèagle¹,

Lochmüller²,

Henkens³

1975

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

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Binding of the substrate, bicarbonate, to bovine cobalt carbonic anhydrase (carbonate hydrolyase, EC 4.2.1.1) has been studied with 13C nuclear magnetic resonance. Two binding sites for bicarbonate have been identified. One loosely binds bicarbonate, inhibits pnitrophenyl acetate activity, and must be the bicarbonate substrate binding site; the other tightly binds bicarbonate, is noninhibitory, and plays another role. Spinlattice relaxation times for the carbon atom of bicarbonate indicate that the substrate bicarbonate is bound directly to the metal center of the enzyme, while the other bicarbonate is bound in the outer coordination sphere of the metal. It is proposed that dehydration proceeds via HCO3-coordinated directly to the metal center, while the outer sphere bicarbonate facilitates catalytically important proton transfers.The zinc metalloenzyme carbonic anhydrase (carbonate hydro-lyase, EC 4.2.1.1) catalyzes the hydration of CO2 and the dehydration of HCO3-with exceptionally high efficiency. Although much is known of the nature of this enzyme, including the structure of the crystalline human c isozyme to a resolution of 2.0 i. (for a recent review see ref. 1), little is known about the nature of its interaction with substrates. It was to increase our understanding of the latter that we undertook a study of bicarbonate binding to carbonic anhydrase using 1"C nuclear relaxation measurements.18C nuclear relaxation is useful for probing structural features of enzyme-substrate interactions, although the first studies of this type have only recently appeared (2-4). In certain cases, paramagnetic enhancement of nuclear relaxation rates provides a measurement of the distance between the paramagnetic center and the bound substrate (for a recent review see ref. 5).In this study, paramagnetic enhancement of bicarbonate 13C relaxation in solutions of cobalt carbonic anhydrase demonstrates that the substrate is weakly bound to the metal center of the enzyme. Further analysis, combined with a comparison of dissociation constants of the enzyme-bicarbonate complex determined from nuclear magnetic resonance (NMR) experiments and from inhibition experiments, reveals a noninhibitory, tightly bound bicarbonate in the outer coordination sphere of the metal. We propose that this tightly bound bicarbonate facilitates the proton transfers that are required for the dehydration of the substrate HC03-and the reverse hydration of CO2. MATERIALS AND METHODSBovine carbonic anhydrase, obtained as a lyophilized material from Worthington Biochemical Corp., was purified by chromatography on Sephadex DEAE A-25 equilibrated with 0.05 M Tris-sulfate buffer, pH 8.7. Elution with the same buffer separated the mixture into three fractions. The first contained carbonic anhydrase, the second superoxide dismutase activity (6), and the third a brownish material, probably derived from hemoglobin.Protein concentrations were determined from the absorbance at 280 nm, using a molar absorptivity of 5.7 X 104 M-1 cm-' (7). Enzymatic activity was...

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The crystal structure of carbonatotetrakis(pyridine)cobalt(III) perchlorate monohydrate

Cited by 13 publications

References 4 publications

The crystal structure of (+)589-cis-β-carbonato-(3S,8S-dimethyltriethylenetetramine)cobalt(III) perchlorate

The crystal structure of (+)589-cis-β-carbonato-(3S,8S-dimethyltriethylenetetramine)cobalt(III) perchlorate

Hydrogen bond directed open-framework of bis(bipyridine-glycoluril) phosphatocobalt(III) with solvent accessible void space

13-C nuclear magnetic resonance studies on the mechanism of action of carbonic anhydrase.

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