Crystal Structures of Magnesium and Calcium Pivalate Hydrates: Mg2Piv4 · 4HPiv · H2O and CaPiv2 · 5H2Oстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:Single crystals of magnesium and calcium pivalate hydrates, g2(-H2)(-Piv)2(Piv)2(HPiv)4 (I)
and {[(-2)(2)(2-,',2-Piv)Piv]}n · {32}n (II), [HPiv = (CH3)3CCOOH], were synthesized
and studied by X-ray diffraction. Compound I crystallizes in the orthorhombic system, a = 12.199(2) Å, b = 19.199(3) Å, c = 48.705(7) Å, Z = 8, space group Pbca, R1 = 0.1371. The crystal structure of compound II (a=11.448(3) Å, b = 24.185(6) Å, c = 6.537(1) Å, =106.41(3), Z = 4) is monoclinic, space group 21/c, R1= 0.0512. In the molecular structure of I, the magnesium atoms are linked in pairs by a bridging water mol-ecule and by two Piv anions to form dimers in which the Mg coordination environment is a distorted [MgO6] tetrahedron with Mg–O distances of 2.02–2.11 Å. The pivalic acid molecules coordinated to the metal atoms are involved in intramolecular hydrogen bonds with monodentate pivalate groups. In the layered structure of II, the calcium atoms with C.N. = 8 and Ca–O distances of 2.347(3)–2.591(3) Å are linked by tetradentate chelat-ing-and-bibridging Piv groups to form polymeric cation ribbons, which alternate with the ribbons of noncoor-dinated Piv anions, thus forming layers due to multiple hydrogen bonds.