COMPOUNDS WITH CLUSTER CATIONS TOGETHER WITH CLUSTER ANIONS [(M6X12)(ETOH)(6)](2-) (M=NB, TA, X=CL, BR) - SYNTHESIS AND CRYSTAL-STRUCTURES() BESIDES [(MO6CL8)CL4X2](2)

Compounds consisting of both cluster cations and cluster anions of the composition [(M6X12)(EtOH)(6)][(Mo6Cl8)Cl4X2]. nEtOH . mEt(2)O (M = N b, Ta; X = Cl, Br) have been prepared by the reaction of (M6X12)X-2 . 6EtOH with (Mo6Cl8)Cl-4. IR data are given for three compounds. The st ructures of [(Nb6Cl12)(EtOH)(6)][(Mo6Cl8)Cl-6]. 3EtOH . 3Et(2)O 1 and [(Ta6Cl12)(EtOH)(6)][(Mo6Cl8)Cl-6]. 6EtOH 2 have been solved in the tr iclinic space group P (1) over bar (No.2). Crystal data: 1, a = 10.641 (2) Angstrom, b = 13.947(2) Angstrom, c = 15.460(3) Angstrom, alpha = 65.71(2)degrees, beta = 73.61(2)degrees, gamma = 85.11(2)degrees, V = 2005.1(8) Angstrom(3) and Z = 1; 2, a = 11.218(2) Angstrom b = 12.723( 3) Angstrom, c = 14.134(3) Angstrom, alpha = 108.06(2)degrees, beta = 101.13(2)degrees, gamma = 91.18(2)degrees, V = 1874.8(7) Angstrom(3) a nd Z = 1. Both structures are built of octahedral [(M6Cl12)(EtOH)6](2) cluster cations and [(Mo6Cl8)Cl-6](2-) cluster anions, forming disto rted CsCl structure types. The Nb-Nb and Ta-Ta bond lengths of 2.904 A ngstrom and 2.872 Angstrom (mean values), respectively, are rather sho rt, indicating weak M-O bonds. All O atoms of coordinated EtOH molecul es are involved in H bridges. The Mo-Mo distances of 2.603 Angstrom an d 2.609 Angstrom (on average) are characteristic for the [(Mo6Cl8)Cb]( 2-) anion, but there is a clear correlation between the number of hydr ogen bridges to the terminal Cl and the corresponding Mo-Cl distances.