Neues aus der Chemie des Berylliums

Recent Advances in the Chemistry of Beryllium A review of recent results in coordination chemistry of beryllium halides is given. In accordance with the editors' objective, this Research Report is not a complete review of the literature in this field, but the important literature close to it is considered. The following subjects are presented: (i) Syntheses and structural characterizations of tetraphenylphosphonium salts of [BeCl 4 ] 2− , [Be 2 Cl 6 ] 2− , and the unique [Be 2 F 6 ] 2− ion, which are soluble in organic solvents like dichloromethane or acetonitrile. (Ph 4 P) 2 [Be 2 F 6 ]·2CH 3 CN is also extensively studied by IR spectroscopy and quantum chemical calculations (DFT). (ii) Application of (Ph 4 ) 2 [Be 2 Cl 6 ] to prepare donor acceptor complexes with N ‐donor ligands D to give complexes [BeCl 3 (D)] − which are isoelectronical with the corresponding boron compounds [BCl 3 (D)], including quantum chemical calculations. (iii) Molecular complexes of the type [BeCl 2 (D) 2 ] with D = phosphorane imines HNPR 3 or Me 3 SiNPR 3 . (iv) Phosphoraneiminato complexes of beryllium, among these the first example [BeCl(μ‐NPEt 3 )] 4 with a Be 4 N 4 heterocubane skeleton. (v) Azido complexes of several types, including the unique examples with adamantane‐like structure [Be 4 X 4 (μ‐N 3 ) 6 ] 2− with X = Cl, Br. (vi) Monocationic complexes [BeCl(12‐crown‐4)] + [SbCl 4 ] − and [BeCl(PMDETA)] + Cl − (PMDETA = pentamethyl‐diethylenetriamine). (vii) Dicationic complexes with O ‐donor ligands H 2 O and OSMe 2 . [Be(OH 2 ) 4 ]Cl 2 , [Be(OSMe 2 ) 4 ]Cl 2 , and mixed ligand complexes like [Be(OH 2 ) 2 (OSMe 2 ) 2 ]Cl 2 . (viii) Molecular and anionic oxo‐complexes, particularly with μ‐OSiMe 3 groups, among these the tetramethyl‐trioxosilanato complex (Ph 4 P) 2 [Be 4 (μ‐Cl) 2 Cl 4 (OSiMe 2 OSiMe 2 O) 2 ].