부산대학교 도서관

The preparation and characterization of two new mixed-valence, trinuclear species, [Mn3O(O2CCF3)6(H2O)3]⋅CF3COOH⋅4/3H2O (1) and [Mn3O(O2CCF3)6(CH3COOH)3] (2), is reported. Compound 1crystallizes in the triclinic space group, P¯1 (No. 2), with the parameters, a=12.3131(9) Å, b=12.4427(9) Å, c=12.965(1) Å, α=72.593(4)°, β=73.453(5)°, γ=68.345(4)°, V=1727.2(2) Å3, and Z=2. A total of 14060 reflections were collected in the range 1.68≤θ≤27.52°. The final weighted and non-weighted agreement indices, R1=0.0589 and wR2=0.1445 were based on a total of 6953 unique reflections with an Rintvalue of 0.0542. Compound 2crystallizes in the monoclinic space group, P21/n(No. 14), with the parameters, a=12.876(3) Å, b=12.212(4) Å, c=17.732(4) Å, β=100.40(3)°, V=3640.4(1) Å3, and Z=4. A total of 32197 reflections were collected in the range 1.72≤θ≤27.13°. The final weighted and non-weighted agreement factors, R1=0.0647 and wR2=0.1609 were based on a total of 8018 unique reflections with an Rintvalue of 0.0462. An investigation of the physical properties revealed that both compounds display an intermediate ground state of S=3/2 as a consequence of intramolecular antiferromagnetic coupling. The magnetic data for compound 1was best fit to the parameters g=2.09, J=−5.5 cm−1, J′=−3.4 cm−1, and DMn(III)=−4.5 cm−1; the data for compound 2was best fit to the parameters g=2.10, J=−2.9 cm−1, J′=−5.5 cm−1, and DMn(III)=−4.5 cm−1.