Affiliation: | aERATO-SORST Kuroda Chiromorphology Team, Japan Science and Technology Agency, 4-7-6 Komaba, Meguro-ku, Tokyo 153-0041, Japan bDepartment of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan |
Abstract: | -Ni(H2O)6 · SO4 and its selenate derivative exhibit chirality only in the solid-state. We have observed, for the first time, a sign inversion of CD (circular dichroism) in the 3A2g → 3T1g(P) Ni(II) d–d transition at near liquid nitrogen temperatures. The novel finding was achieved by building a new cooling unit to a solid-state specialized Universal Chiroptical Spectrophotometer (UCS-1) [R. Kuroda, T. Harada, Y. Shindo, Rev. Sci. Instrum. 72 (2001) 3802.] and by formulating an analytical procedure to obtain artifact-free CD signals based on the Mueller matrix method. The sign inversion is remarkable as the crystal structure hardly changes from 300 to 100 K. The origin of the sign inversion is discussed. |