1:1) / Lithium tetrahydridoborate dimethoxyethane (1:2) / Lithium tetrahydridoborate triglyme (1:1) / Lithium tetrahydridoborate tetrahydrofuran (1:3) / Lithiumtetrahydridoborate 1,3-dioxolane (1:1) / Hydridebridge bonding LiBH 4 • OEt 2 (1) and LiBH 4 • O(Me)CMe 3 (2) form double-centers through two of its four oxygen atoms in such a manner that a chain structure results. The compound LiBH 4 stranded chains in the solid state. While 3 hydrides of the BH 4 group in 1 bind to three different Li atoms through • 3 THF (5) exists as discrete molecules in the lattice. Its BH 4 anion is triply bridging to the Li center. In contrast, Li•••H-B interactions, the fourth H atom interacts with three adjacent Li centers. In contrast, in compound 2 there are two LiBH 4 •C 3 H 6 O 2 (6) (1,3-dioxolane) is polymeric. Due to the presence of two µ 2 2 -BH 4 groups, a chain of the type single Li•••H-B bonds and two doubly bridging hydrogen atoms, the latter again interacting with three lithium centers. •••Li(H 2 BH 2 )Li(H 2 BH 2 )••• is formed, and the 1,3-dioxolane molecules connect the chains through Li-O coordination to Moreover, the arrangements of the ether molecules in 1 and 2 are different. LiBH 4 • 2 DME (3) (DME = dimethoxyethane) form a three-dimensional array. In spite of the variations in the bonding of the BH 4 group to Li centers, the Li atoms are forms a molecular lattice, in which the BH 4 -anions are present in Li•••H 2 BH 2 bridges. The same structural feature is hexacoordinated in 3 to 6 but are heptacoordinated in 1 and 2. present in LiBH 4 • TG ( 4) (TG = triglyme = triethylene glycol dimethyl ether), but the TG molecule coordinates to two Li [᭛] Part 21: Ref. [1] . case of LiBH 4 • 1,4-dioxane [9] due to its very low solubility.