Yoshii Sakai

Ferromagnetic intermolecular interaction in an organic radical e-quinolyl nitronyl nitroxide (3-QNNN)

Abstract A new nitronyl nitroxide radical, 2-(3-quinolyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl-3-oxide, is found to exhibit a ferromagnetic intermolecular interaction with a Weiss constant Θ=0.27 K. The crystal structure is described and the relationship with the intermolecular interaction is discussed.

[(R)-1,2-Bis(allyloxycarbonyl)ethyl]bis(dimethylglyoximato-N,N')[(R)-1-phenylethylamine]cobalt(III)

A new bis(dimethylglyoximato)cobalt(III) complex with a bulky chiral alkyl group bonded to the Co atom has been prepared, [Co(C4H7N2O2)2(C10H13O4)(C8H11N)]. The crystal was irradiated with a xenon lamp. Racemization of the crystalline state was not observed for the crystal since the reaction cavity for the chiral alkyl group appears to be too small.

Ferro- and Anteferromagnettc Interactions and Crystal Structures of Some Organic Radicals Based on Nitronyl Nitroxide

Abstract Our recent results of magnetization, susceptibility and electron paramagnetic resonance (EPR) measurements and crystal structure determinations for the organic radiclals based on a-nitronyl nitroxide are described. The 3-quinolyl derivative with ferromagnetic intermolecular interaction shows a considerable shift of resonance field in EPR at low temperature probably due to short-range magnetic-order formation. The p-diethylaminophenyl derivative is characterized as a typical one-dimensional Heisenberg antiferromagnet.

Structure of an optically active anthracycline precursor

The crystal structure of (1S,3S)-3-acetyl-5-methoxy-3-methylthio-1,2,3,4-tetrahydronaphtalene-1,8-diyl dibenzoate contains two independent molecules. These molecules have a similar conformation except for the dihedral angles between the aromatic ring and the benzoyloxy group linked to it, witch differ by a relative rotation of -160 o . The absolute configurations of the two citral centres C8 and C10 are established as S and S

Structure of endo-(5S*,6S*,11R*,12R*)-5,6,11,12-tetrahydro-5,6-dihydroxy-4,11,12-trimethoxy-9,13,13-trimethyl-6,10-methano-8(7H)-benzocyclodecenone

It has been confirmed that the title molecule has three fused rings consisting of a six-membered, an eight-membered and a benzene ring. The six-membered ring has a twisted C=C double bond; the dihedral angle between the planes of C10, C11, C15 and C13, C12, C18 is 22.1 (3) o [IUPAC numbering: C11-C10-C(methano) and C8-C9-C(methyl), respectively]. The eight-membered ring adopts a chair-boat conformation