Tetra(N,N′‐tetramethylharnstoff)‐Beryllium‐Triiodid, [Be(TMH)₄](I₃)₂

Abstract

Tetra(N,N′‐tetramethylurea)‐beryllium‐triiodide, [Be(TMU)4](I3)2 (1) was prepared from beryllium powder and iodine in N,N′‐tetramethylurea to give orange crystals, which were characterized by X‐ray diffraction and IR spectroscopy. Compound 1 crystallizes monoclinically in the space group C2/c with four formula units per unit cell. Lattice dimensions at 100(2) K: a = 1906.6(1), b = 1185.7(1), c = 1895.0(1) pm, β = 113.60(1) °, R1 = 0.0291. The structure of 1 consists of distorted tetrahedral cations [Be(TMU)4]2+ with Be–O bond lengths of 162.5(5) and 160.8(5) pm and triiodide ions without site symmetry.

Recent Contributions to the Coordination Chemistry of Beryllium

“…[97,99] This is in line with the fact that even in aqueous solutions BeF 2 does not dissociate completely. [100] Like H 2 Oa nd NH 3 ,a lso other strong donor ligands like tetramethylurea, pyridine, diisopropylcarbodiimide, or dimethyl sulfoxide (DMSO) can displace chloride to give dicationic complexes 114, [101] 115, [102] 116, [103] and 117, [104] respectively (Figure 14). However,t he strong affinity of beryllium atoms for aqua ligandsi se vident from the fact that DMSO ligandsa re displaced by H 2 Ow hen complex cation 117 is exposed to air.T his gives rise to the formation of mixed cations 118 and 119.…”

Synthesis and Characterization of Cp*Be‐F‐Al(ORF)3

“…Due to the extreme Lewis acidity and hardness of the Be 2+ cation, it needs strong, preferably oxygen‐based donor ligands, to keep counterions away from coordinating to it. While [BeL 4 ] 2+ salts with L = H 2 O9–12 are well known to form in aqueous solutions, some other dicationic salts with oxygen‐based ligands L = DMSO,13,14 or N , N ′‐tetramethylurea15 have been synthesized over the last years. Neumüller and Dehnicke reported on dicationic beryllium salts with the nitrogen donor ligands pyridine,16 N ‐methylimidazole,17 and N , N ′‐diisopropylcarbodiimide 18.…”

[Be3(μ3‐O)3(MeCN)6{Be(MeCN)3}3](I)6 – ein Berylliumkomplex mit Cyclo‐(Be3O3)‐Kern und sein Hydrolyseprodukt [Be(H2O)4](I)2·2MeCN

“…Berylliumpulver und Iod reagieren mit einer Reihe überschüssiger Lewis‐basischer Ligandmoleküle L bereits bei Raumtemperatur in langsamer, exothermer Reaktion unter Bildung der entsprechenden solvatisierten Dikationen [Be(L) 4 ] 2+ mit Iodid oder Polyiodiden als Gegenionen, wobei die Ligandmoleküle als Reaktanden und Lösungsmittel zugleich fungieren. Wir haben diesen neuen präparativen Reaktionstyp anhand der stark basischen Solvatreagentien L = Pyridin, 1 Tetramethylharnstoff, 2 Diisopropylcyanamid 3 und N ‐Methylimidazol 4 geprüft und die resultierenden Komplexverbindungen kristallographisch und schwingungsspektroskopisch charakterisiert.…”