Ein anorganischer Cryptand: schrittweise Synthese und Koordination von Li⁺‐Ionen

Abstract

Nach organischem Vorbild: Der anorganische Cryptand [P2{O(SiiPr2)2}2{SiMe2(OSiMe2)2}] (siehe Bild, C schwarz, O orange, P rot, Si blau) kann schrittweise durch einen Lithiierungs‐Silylierungs‐Prozess aufgebaut werden. Eine erste Koordinationsverbindung dieses Liganden wurde bei der Reaktion mit Li[Al(ORF)4] erhalten.

Coordination and Oligomerisation of the Siloxanephosphane Cage Compound [P2{(SiMe2)2O}3]

“…These NMR spectra indicate that the re- (5) with four equivalent phosphorus atoms. The formation of 5 and [Li@5] + was further investigated by ESI-MS. [5,7,8] The strongest signal observed in the positiveion mass spectrum appeared at approximately m/z = 923 and can be clearly assigned to the complex ion [Li@5] + (see the Supporting Information), proving dimerisation of 2 and complexation of Li + in solution. For such an ion, two different structures are feasible: a) A lithium ion centred in an adamantane-like cage, which leads to tetrahedral coordination of the metal ion by the phosphorus atoms, or b) a less symmetric ligand, in which the phosphorus atoms are in one plane and are alternately bridged by one or two siloxane bridges ( Figure 4).…”

“…This analogy could be confirmed by the synthesis of the lithium complex [Li@1] + (see Scheme 1). [5] The large distances between the phosphorus and the lithium atoms within the complex [Li@1] + , as well as the fact that only three of the four oxygen atoms coordinate to the lithium ion, led us to question whether a smaller cage with three disiloxane bridges instead of two disiloxane and one trisiloxane bridges could still accomodate a Li + ion. A cage of this kind with the composition [P 2 A C H T U N G T R E N N U N G {(SiMe 2 ) 2 O} 3 ] (2) could be obtained from the reaction of OA C H T U N G T R E N N U N G (SiMe 2 Cl) 2 with [Li-A C H T U N G T R E N N U N G (dme)PH 2 ] in diethyl ether.…”

“…[2] In 2006 the group of Passmore was able to synthesise complexes of the ligands (SiMe 2 O) 5 and (SiMe 2 O) 6 (D5 and D6, respectively) systematically by reactions with the lithium salt of the weakly coordinating anion [AlA C H T U N G T R E N N U N G (OR F ) 4 ] À . [3] In the obtained products [Li@D5] 4 ], the lithium ion is located in the middle of the almost planar siloxane rings.…”

A Noble‐Metalate Bowl: The Polyoxo‐6‐vanado(V)‐7‐palladate(II) [Pd7V6O24(OH)2]6−

“…[16][17][18] The ESI-FT mass spectrum is shown in Figure 4. Peak 5 can be unambiguously assigned to the singly charged molecular cation {K 7 …”

Synthesis and Coordination of the Cagelike Siloxane Compounds E2{(SiMe2)2O}3 (E = As, Sb, Bi)

“…(M = Al, E = As, Sb; M = Ga, E = Sb) Lewis acid-base adducts were formed as well as the W(CO) 5 adduct of compound 1 and a heteroleptic Na[Al(OR F ) 4 ] (R F = C(CF 3 ) 3 ) adduct with 4 to investigate the coordination properties of the cage compounds. The structural changes caused by coordination follow the Haaland model, which gives qualitative information on the adduct stability.…”