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Three cucurbit[6]uril (CB[6])-based polyrotaxanes [Cu(H2 C6N4)(CB[6])]Cl4·12H2O (1), [Co(H2 C6N4)(CB[6])]Cl4·14H2O (2) and [Ag(C6N4)(CB[6])]NO3·7H2O (3) are prepared using N,N′-bis(4-pyridylmethyl)-1,6-hexanediamine (C6N4) threading into CB[6]'s and metal ions' assistance. Single-crystal X-ray diffraction analyses reveal that polyrotaxanes 1, 2 and 3 all have 1D chain structure where 1 and 2 are linear and 3 has two shapes, linear and sawtooth, respectively. The effects of guest molecules, metal and counter ions as well as intermolecular weak interactions on the architectures of polyrotaxanes are discussed.

A pseudo-rotaxane, [(H2C6N3)(CB[6])](NO3)2·H2O (1), and three polyrotaxanes, [Ag(H2C6N3)(CB[6])](NO3)3·8H2O (2), [Ag(H2BDMN3)(CB[6])](NO3)3·10H2O (3), and [Ag(H2BDMN3)(CB[6])(H2O)][Ag(H2BDMN3)(CB[6...

The inclusion behavior between Costa-type complexes and cyclodextrins (CDs) was studied by 1H NMR in aqueous solution. The results indicated that 1:1 inclusion complex was formed, in which the alkyl group of the guest was included in the cavity of CDs. The stability constants of the inclusion complexes were determined by the quantitative 1H NMR method. The effects on stability constants were discussed when various host and guest compounds were used.

The crystal and molecular structures of alkylcobaloxime/ g -cyclodextrin ( g -CD) inclusion complexes: butyl(aqua)cobaloxime/ g -CD ( 1 ). hexyl(aqua)cobaloxime/ g -CD ( 2 ) and cyclohexyl(aqua)cobaloxime/ g -CD ( 3 ) were determined by X-ray diffraction analyses. Crystal data for 1 ·14H 2 O: P 2 1 2 1 2 1 , a =15.1335(3), b =18.9630(2), c =28.1545(5) A, Z =4; 2 ·12H 2 O: P 2 1 2 1 2 1 , a =15.1135(4), b =19.1477(5), c =28.2715(7) A, Z =4; 3 ·10H 2 O: P 2 1 2 1 2 1 , a =15.6898(2), b =16.9094(2), c =28.9762(2) A, Z =4. The structural and conformational comparisons for the three g -CD inclusion complexes with their guest molecules as well as other CD inclusion analogs are discussed.

The crystal structure of the aqua(butyl)cobaloxime/α-cyclodextrin inclusion complex was determined by single X-ray diffraction. It crystallizes in the orthorhombic space group P212121 with a = 14.083(3), b = 19.237(4), c = 24.517(5) A and Z = 4. A thermogravimetric analysis has indicated that the thermal stability of the aqua(butyl) cobaloxime was increased in its α-cyclodextrin inclusion complex.

Aqua(2-methoxycarbonylethyl)cobaloxime 1 and its β-cyclodextrin inclusion complex 2 were synthesized and characterized by 1H NMR and X-ray crystallography. Structural and conformational comparisons between the inclusion complex and the guest compound are made. The rearrangement reaction of the methoxycarbonylethyl radical was observed in the anaerobic photolysis of aqua(2-methoxycarbonylethyl)cobaloxime in the absence and presence of β-cyclodextrin by using the EPR spin-trapping technique. The changes of EPR parameters indicate that the formed spin adduct could be included in the β-cyclodextrin’s cavity.

The crystal and molecular structures of iso-butyl(aqua)cobaloxime (I) and its hydrated inclusion complexes with α-cyclodextrin (II) and β-cyclodextrin (III) were determined by X-ray diffraction ana...

A series of inclusion complexes involving α-cyclodextrin (α-cd) and alkyl(aqua)cobaloximes has been synthesized for the first time and characterized by elemental analysis, one and two-dimensional 1H NMR spectroscopy. Their formation constants Ka were determined by quantitative 1H NMR methods. The crystal structures of α-cd–[Co(Hdmg)2Prn(H2O)](H2dmg = dimethylglyoxime) and its guest molecule [Co(Hdmg)2Prn(H2O)] were determined. According to both NMR and crystal structure data, 1 : 1 inclusion complexes of α-cd and alkylcobaloximes are formed, in which the alkyl groups of the guests are included into the cavity of α-cd. After formation of the inclusion complexes, variations in the bond lengths and angles around the cobalt atom, and conformation changes of the n-propyl(aqua)cobaloxime were observed. It is suggested that these changes in the guest molecule are probably due to the hydrophobic interaction between the alkyl groups and the α-cd cavities, and steric interaction between α-cd and Co(Hdmg)2. It has also been established that the stability of the inclusion complexes in aqueous solution is related to the length and the size of the alkyl groups, the Ka values varying in the order n-C5H11 Bun > Prn > Bui.

The title compound, 3,3'-(4-pyridylimino)dipropanenitrile, C 11 H 12 N 4 , has a twofold axis and consists of a pyridine ring head and two cyanoethyl tails, the three groups being linked by an N atom. The planar geometry around the amino N atom suggests conjugation with the π-system of the pyridine ring. The molecules are stacked in a layer structure via relatively weak to very weak intermolecular C-H...π and C-H...N hydrogen-bond interactions.

A cobalt-to-oxime carbon bridged organocobaloxime/β-cyclodextrin inclusion complex has been formed in a β-cyclodextrin induced reaction, which was confirmed by X-ray structure analysis and FAB-MS.

The crystal structure determination of the title compound, a model for coenzyme B12, indicates that it is [Co(C4H6N2O2)(C5H9)(C4H8N2O2)(H2O)], i.e. one 2,3-butanedione dioxime ligand is neutral and the second is a dianion, with the CoIII ion in a distorted octahedral environment. The axial Co—C bond length [2.029 (2) A] is close to that of coenzyme B12[2.00 (1) A].

A dimeric Co(II) complex of ferron (=7-iodo-8-hydroxy-quinoline-5-sulfonate) was isolated as crystals and structurally characterized. Weak IH and IC interactions involving the iodoquinoline rings and complementary steric requirements for II contacts led to self-assembly of the complex, which indicates versatile nature of the iodine atom in intermolecular interactions.