Microcalorimetric investigation on formation of the ellipsoidal Mo-blue ring coordinated by La3+ cations

INOR 701

Eri Ishikawa, eri_ishikawa@res.titech.ac.jp and Toshihiro Yamase, tyamase@res.titech.ac.jp. Chemical Resources Laboratory, Tokyo Institute of Technology, R1-21 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
La3+-coordinated Mo-blue nano-ring, [Mo130O402H16(H2O)46{La(H2O)5}4{La(H2O)7}4{LaCl2(H2O)5}2]10- ({Mo130 (La)10}), produced by reaction between [Mo142O429H10(H2O)49(CH3CO2)5 (C2H5CO2)]30- ({Mo142 (Ac)5 (Pr)}) and La3+ in aqueous solutions, has been X-ray crystallographically characterized as a sodium salt. The {Mo130 (La)10} anion shows an ellipsoidal structure with 3.6 and 3.1 nm of long and short axes for the outer ring diameters, which results from the tricapped trigonal prismatic coordination of LaO9 on the inner rings. The results of the isothermal titration-calorimetry (ITC) indicated endothermic reaction of [La3+]/[{Mo142 (Ac) 5 (Pr)}] = 6/1 for the capture of three La3+ cations on the three {Mo2}2+-defect parts for each inner ring, which are 139La-nmr inactive.
 

Polyoxometalates and Related Clusters in Chemistry and Nanoscience
7:00 PM-10:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Inorganic Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007