Structures of racemic lithium tartrate hydrates

Abstract

Racemic dimetal tartrate hydrates were obtained from the reaction of d, l-tartaric acid with LiOH and MOH, where M = Li, Na, K, Rb, Cs, NH 4. Dilithium trihydrate Li 2(C 4H 4O 6) · 3H 2O ( 1) consists of two distinct two-dimensional coordination networks [Li 6(C 4H 4O 6) 3(H 2O) 9] n (A) and [Li 2(C 4H 4O 6)(H 2O) 3] 2 n (B) which are arranged parallel in BAABAA fashion. Lithium sodium dihydrate LiNa(C 4H 4O 6) · 2H 2O ( 2) is as a three-dimensional coordination network in which discrete centrosymmetric [Li(C 4H 4O 6)(H 2O)] 2 units are linked by NaO 6 polyhedra. The monohydrates LiM(C 4H 4O 6) · H 2O with M = K ( 3), Rb ( 4), Cs ( 5) are three-dimensional coordination networks which are isostructural with the hydrogen-bonded ammonium analogue, M = NH 4 ( 6). These structures are composed of [LiM(C 4H 4O 6)(H 2O)] n layers linked by MO 8 and MO 10 polyhedra. Different patterns of hydrogen bonding between tartrate ions and water molecules are observed in structures 1, 2 and the series of 3– 6.