A three-dimensional ferromagnet, [Ni(dipn)]3[Cr(CN)6]2.3H2O (dipn = dipropylene triamine), based on a cubic Cr8Ni12 unit

Wakako Kaneko; Masaaki Ohba; Hisashi Okawa; Susumu Kitagawa

doi:10.1021/ic0606882

A three-dimensional ferromagnet, [Ni(dipn)]3[Cr(CN)6]2.3H2O (dipn = dipropylene triamine), based on a cubic Cr8Ni12 unit

Inorg Chem. 2006 Sep 4;45(18):7191-6. doi: 10.1021/ic0606882.

Authors

Wakako Kaneko¹, Masaaki Ohba, Hisashi Okawa, Susumu Kitagawa

Affiliation

¹ Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.

PMID: 16933919
DOI: 10.1021/ic0606882

Abstract

The combination of Ni2+, dipropylenetriamine (dipn), and [Cr(CN)6]3- affords the cyanide-bridged bimetallic assembly, [Ni(dipn)]3[Cr(CN)6]2.3H2O (1). This compound crystallizes in cubic space group Pa, with a = b = c = 20.9742(7) A and Z = 8. A three-dimensional network is constructed on the basis of a Cr8Ni12 cubane unit formed by an alternate array of [Cr(CN)6]3- and [Ni(dipn)]2+ units through Cr-CN-Ni-NC-Cr edges. Cryomagnetic studies reveal a ferromagnetic interaction between Cr(III) and Ni(II) ions and a long-range ferromagnetic ordering below 42 K with very small coercive field. To the best of our knowledge, this compound is the first "complete ferromagnet" providing three-dimensional ferromagnetic interaction through a three-dimensional bridging structure that is based on a cubic unit among general metal-oxide and molecule-based magnets. Magnetooptical studies demonstrate a strong correlation between magnetic and optical properties.