Hydrothermal reaction of terbium(Ⅲ) chloride with 5-sulfoisophthalic acid monosodium salt and 1,10-phenanthroline(phen) at 415 K resulted in the formation of a novel coordination polymer, [Tb(sip)(phen)(H2O)]n(sip=5-sulfoisophthalate trivalent anion) with a three-dimensional network structure. Each centrosymmetrically related pair of terbium ions are linked by two sip anions, forming a binuclear unit, and each binuclear unit links to four adjacent tetranuclear units, extending a two-dimensional hybrid layer at crystallographic bc plane. On the other hand, every three-terbium ion is connected by three sip anions, generating a trinuclear ring, and the trinuclear ring connects six neighboring trinuclear rings to produce another two-dimensional layer at crystallographic ab plane. Moreover, each sip anion acts as a pentadentate bridge, interconnecting two different types of layers to yield a novel three-dimensional framework.
