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Swift oxo transfer reactions of perchlorate and other substrates catalyzed by rhenium oxazoline and thiazoline complexes.

The reaction kinetics and mechanisms of catalytic oxygen atom transfer (OAT) with rhenium oxazoline and thiazoline complexes are described in this feature article. The striking features of this new family of molecular oxotransferases are their rapid kinetics and their surpassed ability in catalyzing the very difficult reduction of perchlorate by atom transfer. The diverse and competing pathways that make these catalysts efficient and practical have been delineated. Factors that govern the rates of OAT reactions have been elucidated on the basis of substrate variation, substituent and steric effects, subtle changes in the coordination environment, and geometrical transformations. This account also presents comparisons of our abiological OAT catalysis to mechanistically related enzymes and model complexes of molybdenum and tungsten.

Journal Article↗

Donor effect on supramolecular structures of silver(I) perchlorate complexes of macrocycles with O2S2X (X=S, O and NH) donor sets.

By virtue of simple one donor variations of O(2)S(2)X-donor macrocycles (L(1): X=S, L(2): X=O and L(3): X=NH) towards silver(I) perchlorates, four supramolecular complexes (1-3) with different topologies have been isolated; L(1) afforded solvent- and anion-free sandwich complex (1), otherwise L(2) and L(3) gave the dimeric (2a), 1-D polymeric (2b), and tetrameric bowl-type (3) complexes with solvent or anion coordination.

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Verification of Intoximeter 3000 breath alcohol concentration by magnesium perchlorate tube method in long-term field program.

The anhydrous magnesium perchlorate (MPT) breath alcohol sample collection tube was analyzed by gas chromatography (GC) to verify paired breath alcohol concentrations obtained from 18 Intoximeter 3000 (IR) instruments under normal conditions of use. This study compares the accuracy, precision, and reliability of actual driving-while-intoxicated (DWI) IR breath alcohol evidence gathered by field law enforcement personnel with the GC results of the MPT alcohol analysis. The IR and MPT-GC breath alcohol concentration results from a total of 1024 individuals were determined. Results of 530 (51.7%) MPT-GC breath alcohol analyses deviated within +/- 0.010 g/210 L from their paired IR breath alcohol result; 817 (79.7%) and 945 (92.3%) MPT-GC breath alcohol analyses deviated within +/- 0.020 and +/- 0.030 g/210 L, respectively. Confidence interval limits at various probability levels are tabulated and show expected reliability of a single predicted IR breath alcohol concentration from the IR on MPT-GC linear regression analysis.

Alcoholic Intoxication↗

2,2'-Bipyridinium bis(perchlorate)

The title compound, [H(2)bipy](ClO(4))(2) or C(10)H(10)N(2)(2+). 2ClO(4)(-), was obtained at the interface between an organic (2, 2'-bipyridine in methanol) and an aqueous phase (perchloric acid in water). The compound crystallizes in space group P-1 and comprises discrete diprotonated trans-bipyridinium cations, [H(2)bipy](2+), and ClO(4)(-) anions. The cations and anions are connected through N-H.O and C-H.O hydrogen bonds [distances N.O 2.817 (4) and 2.852 (4) A, and C.O 3.225 (6)-3.412 (5)A]. The C-C bond distance between the two rings is 1.452 (5) A. The bipyridinium cation has a trans conformation and the N-C-C-N torsion angle is 152.0 (3) degrees.

Journal Article↗

Bis[3,6-bis(6-methyl-2pyridyl)pyridazine-kappa2N2,N3]chlorocopper(II) perchlorate.

The title compound, [CuCl(C16H14N4)2]ClO4, consists of a mononuclear complex cation and a perchlorate anion. The coordination of the copper(II) ion exhibits a trigonal bipyramidal geometry, where the equatorial plane is composed of the Cl atom and two N atoms of the two pyridazine rings, and the axial positions are occupied by the N atoms of two methylpyridine rings.

Crystallography, X-Ray↗

(C-rac-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetraazacyclotetradecane-kappa4N)(nicotinato-O,O')nickel(II) perchlorate.

In the title compound, [Ni(C(6)H(4)NO(2))(C(16)H(36)N(4))]ClO(4), the macrocyclic unit adopts a folded conformation, allowing the two carboxyl O atoms to occupy two neighbouring coordination sites and thus form an additional four-membered chelate ring. The less crowded side of the macrocycle (that with the two asymmetric C-H groups) is directed towards the nicotinate anion and the asymmetric C-CH(3) groups are directed away from it. The macrocyclic NH groups neighbouring the C-CH(3) groups are also directed away from the nicotinate anion, while those NH groups which are near to the geminal methyl groups are directed towards the nicotinate anion. Although the complex does not include water molecules, three types of hydrogen bond were found, involving NH groups of the macrocyclic ligand, pyridine N atoms and O atoms of the perchlorate anions.

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A pseudo-cage complex of silver(I) with tripodal tetraamine having benzyl end groups, [tris[2-(benzylamino)ethyl]amine-kappa 4N]silver(I) perchlorate.

The synthesis and crystal structure of [tris[2-(benzylamino)ethyl]amine-kappa(4)N]silver(I) perchlorate, [Ag(C(27)H(36)N(4))]ClO(4) or [Ag(bz(3)tren)]ClO(4) [bz(3)tren is tris[2-(benzylamino)ethyl]amine or N,N',N''-tribenzyltris(2-aminoethyl)amine] are reported. The Ag atom is coordinated to four N atoms of the tren unit and is located 0.604 (3) A out of the trigonal plane described by the three secondary amine N atoms, away from the bridgehead N atom. Edge-to-face pi-pi interactions between the aromatic end groups, and weak interactions between Ag and arene, allow the formation of a pseudo-cage complex.

Journal Article↗

Low-dimensional compounds containing cyano groups. IV. Bis(2,2'-bipyridine-kappa(2)N,N1)(dicyanamido-kappaN')copper(II) perchlorate and mu-dicyanamido-kappa(2)N1:N5-bis[bis(2,2'-bipyridine-kappa(2)N,N')copper(II)] triperchlorate ethanol hemisolvate, complexes with unusual dicyanamide coordination.

From reaction mixtures containing the same reagents, the two novel title complexes, with unusual coordination modes of the dicyanamide (dca) ligand, have been prepared. The first compound, [Cu(C(2)N(3))(C(10)H(8)N(2))(2)]ClO(4), represents a relatively rare class of compounds, with the dca ligand coordinated in a monodentate manner. Its structure is formed by the [Cu(bpy)(2)N(CN)(2)](+) complex cation (bpy is 2,2'-bipyridine) and a ClO(4)(-) anion, which does not enter the inner coordination sphere. The Cu centre is five-coordinate within a strongly distorted trigonal bipyramid to two bpy molecules and one dca ligand, which is coordinated through one nitrile N atom in the equatorial plane. The second compound, [Cu(2)(C(2)N(3))(C(10)H(8)N(2))(4)](ClO(4))(3).0.5C(2)H(6)O, contains dca coordinated in the more common bidentate manner, but instead of a chain structure, a unique binuclear complex is formed. The asymmetric unit consists of the [Cu(bpy)(2)N(CN)(2)(bpy)(2)Cu](3+) binuclear complex cation, the charge of which is neutralized by three uncoordinated perchlorate anions, and a half-molecule of ethanol. Both Cu centres in the cation are five-coordinate, adopting a slightly distorted trigonal-bipyramidal environment.

Journal Article↗

A perchlorate salt of an octaprotonated cryptand.

The title compound, 1,4,8,11,14,18,23,27-octaaza-6,16,25(2,6)- tripyridinabicyclo[9.9.9]nonacosaphane(8+) octaperchlorate pentahydrate, C(33)H(59)N(11)(8+) x 8ClO(4)(-) x 5H(2)O, is a salt of an octaprotonated cryptand in which one of the pyridine groups and the bridgehead tertiary amines remain unprotonated. The central cavity of the cryptand is not occupied, although the perchlorate ions are hydrogen bonded in clefts formed between the arms of the cryptand.

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Three-dimensional hydrogen-bonding supramolecular architecture of 2-(3-pyridinio)-5-(3-pyridyl)-1,3,4-oxadiazole perchlorate.

In the crystal structure of the title compound, C(12)H(9)N(4)O(+).ClO(4)(-), the protonated cation adopts a cis-I conformation and approximately planar geometry. Each perchlorate anion acts as the acceptor of three C-H...O weak interactions, which, together with N-H...N and C-H...N hydrogen bonds between the protonated cations, extend this structure into a three-dimensional hydrogen-bonded network.

Journal Article↗

(4,4,12,12-Tetramethyl-5,8,11-triazapenta-2,14-dione 2-oxime 14-oximato-kappa(5)N)copper(II) perchlorate: a copper(II) compound with a pentadentate triamine-oxime-oximate ligand.

The title compound, [Cu(C(16)H(34)N(5)O(2))]ClO(4), has discrete square-pyramidal (triamine-oxime-oximato)copper(II) cations and perchlorate anions. The cations have very approximate mirror symmetry, with the oxime [Cu-N = 2.066 (2) A], oximate [Cu-N = 2.087 (2) A] and amine N atoms [Cu-N = 2.138 (2) and 2.095 (2) A] in the tetrahedrally twisted basal plane, and the 'central' amine N atom coordinated axially [Cu-N = 2.183 (2) A]. The oxime and oximate groups are linked by an O-H.O hydrogen bond, forming a pseudo-cyclic pentadentate ligand, with an O.O distance of 2.395 (3) A.

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Polar hydrogen-bonded organic chains in 4,4'-bipyrazolium bromide and perchlorate monohydrates.

4,4'-Bipyrazolium [or 4-(1H-pyrazol-4-yl)pyrazolium] bromide monohydrate, C6H7N4+.Br-.H2O, and 4,4'-bipyrazolium perchlorate monohydrate, C6H7N4+.ClO4-.H2O, have closely related layered structures involving tight stacks of antiparallel N-H...N hydrogen-bonded polar bipyrazolium chains [N...N = 2.712 (3) and 2.742 (2) A], which are crosslinked by hydrogen bonds with water molecules and counter-anions.

Journal Article↗

Silver(I) complexes of 2-(2-aminoethyl)pyridine: nitrate and perchlorate salts of bis[mu-2-(2-aminoethyl)pyridine-kappa(2)N:N']disilver(I).

2-(2-Aminoethyl)pyridine (2-aep, C7H10N2) acts as a bridging ligand in bis[mu-2-(2-aminoethyl)pyridine-kappa(2)N:N']disilver(I) dinitrate, [Ag2(2-aep)2](NO3)2, and bis[mu-2-(2-aminoethyl)pyridine-kappa(2)N:N']disilver(I) diperchlorate, [Ag2(2-aep)2](ClO4)2. Both salts contain the dinuclear [Ag2(2-aep)2]2+ cation, which possesses a crystallographic inversion center. The Ag...Ag distance is 3.1163 (5) A for the nitrate and 3.0923 (3) A for the perchlorate salt, and may indicate a weak d(10)-d(10) interaction in each case. Essentially linear coordination of the AgI atom is perturbed by weak coordination to the anionic O atoms. These latter interactions organize the dinuclear cations into one-dimensional polymeric chains in the crystals of the two salts.

Journal Article↗

Low-dimensional compounds containing cyano groups. XII. Bis(1,3-diaminopropane-kappa2N,N')(dicyanamido-kappaNPart XI: Potocnák, Burcák, Baran and Jäger (2005).)copper(II) perchlorate.

The title compound, [Cu(C2N3)(C3H10N2)2]ClO4, is made up of [Cu(tn)2{N(CN)2}]+ complex cations (tn is 1,3-diaminopropane) and ClO4- anions. The Cu(II) atom is coordinated by four N atoms of two equatorial tn ligands, with an average distance of 2.041 (7) A, and one nitrile N atom of the dicyanamide anion in an axial position, at a distance of 2.236 (3) A, in a manner approaching square-planar coordination geometry. The complex has C(s) symmetry, with the mirror plane lying through the central C atoms of both tn ligands and the dca ligand. The ClO4- anion might be considered as very weakly coordinated in the opposite axial position [Cu-O = 2.705 (3) A], thus completing the Cu(II) coordination to asymmetric elongated octahedral (4+1+1*). The Cu atom and the perchlorate anion both lie on mirror planes.

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(Acetonitrile-kappaN){2-[bis(2-pyridylethyl)amino]ethanol-kappa4N,N',N'',O}zinc(II) bis(perchlorate) monohydrate.

In the title compound, [Zn(C2H3N)(C16H21N3O)](ClO4)2.H2O, the Zn(II) ion is coordinated by two pyridyl N atoms, one amine N atom, and an ethanol O atom from the N,N',N'',O-tetradentate 2-[bis(2-pyridylethyl)amino]ethanol donor ligand. The fifth coordination site is filled by an acetonitrile N atom, and there is one solvent water molecule in the asymmetric unit. The 2+ charge of the cationic portion of the complex is balanced by two perchlorate counter-anions.

Journal Article↗

{mu-N,N'-Bis[3-(dimethylamino)propyl]oxamidato(2-)-kappa(6)N,N',O':N'',N''',O}bis[(1H-imidazole-kappaN3)(methanol-kappaO)copper(II)] bis(perchlorate).

The structure of the title compound, [Cu2(C12H24N4O2)(C3H4N2)2(CH4O)2](ClO4)2 or [Cu2(dmoxpn)(HIm)2(CH3OH)2](ClO4)2, where dmoxpn is the dianion of N,N'-bis[3-(dimethylamino)propyl]oxamide and HIm is imidazole, consists of a centrosymmetric trans-oxamidate-bridged copper(II) binuclear cation, having an inversion centre at the mid-point of the central C-C bond, and two perchlorate anions. The Cu(II) atom has square-pyramidal coordination geometry involving two N atoms and an O atom from the dmoxpn ligand, an N atom from an imidazole ring, and an O atom from a methanol molecule. The crystal structure is stabilized by O-H...O, N-H...O and C-H...O hydrogen bonds and imidazole pi-pi stacking interactions to form a three-dimensional supramolecular array.

Copper↗