Synthesis of 2,2′,5,5′-Tetraphenyl-1,1′-diarsacalcocene and -strontocene

Abstract

The metalation of H2As−SiiPr3 with bis(tetrahydrofuran‐O)calcium‐ and ‐strontium bis[bis(trimethylsilyl)amide] yields tetrakis(tetrahydrofuran‐O)calcium‐ (1a) and ‐strontium bis(triisopropylsilylarsanide) (2a). These compounds are in equilibrium with their dimers 1b (Ca) and 2b (Sr) by elimination of THF. The addition of diphenylbutadiyne to a THF/toluene solution of 1 and 2 gives bis(tetrahydrofuran‐O)calcium‐ (3) and ‐strontium bis(2,5‐diphenylarsolide) (4). The proposed reaction mechanism explains the formation of the (iPr3Si)2As− and 2,5‐diphenyl‐3,4‐bis(phenylethynyl)arsolide anions based on an intermolecular H/SiiPr3 exchange reaction. The latter anion was characterized by X‐ray crystallography with the binuclear cation [(THF)3Ca{µ‐As(H)SiiPr3}3Ca(THF)3]+ (5). The arsolide ligands of 3 and 4 are η5‐bonded to the metal centers, whereas 5 crystallizes as a solvent‐separated ion pair.

Arsenic‐Mediated C−C Coupling of Cyanides Leading to Cyanido Arsazolide [AsC4N4]−

“…[15] While af ew cationic diazarsenium [16][17][18] (A [16] d(AsÀN) = 1.763, B [19] 1.803-1.814 )a nd neutral tetrazaarsole (d(AsÀN) = 1.784-1.805 ) [20] heterocycles are known (Scheme 3, species A-C), anionic diazarsolides are hitherto unknown. [22] Arsolides of the type [R 4 C 4 As] À (R=Ph, Et) were described by Westerhausen et al [23,24] Neutral group 16 analogues of [AsC 4 N 4 ] À were obtained in the reaction of 2,3-diaminomaleonitrile with ECl 4 (E=Se, Te )i nt he presence of organic bases. [22] Arsolides of the type [R 4 C 4 As] À (R=Ph, Et) were described by Westerhausen et al [23,24] Neutral group 16 analogues of [AsC 4 N 4 ] À were obtained in the reaction of 2,3-diaminomaleonitrile with ECl 4 (E=Se, Te )i nt he presence of organic bases.…”

Alkaline Earth Organometallics

“…The strontocene crystallizes as a THF adduct whereas the barocene 157 precipitates co-ligand-free but as a coordination polymer ( Figure 83). 362 Subsequent reaction with diphenylbutadiyne in toluene/THF gives the metal bis(THF)bis(2,5-diphenylarsolide) species. 362 Subsequent reaction with diphenylbutadiyne in toluene/THF gives the metal bis(THF)bis(2,5-diphenylarsolide) species.…”

Aufbau von Erdalkalimetall-Arsen-Käfigstrukturen durch die Metallierung von Triisopropylsilylarsan mit Calcium-, Strontiumund Barium-bis[bis(trimethylsilyl)amid] in Tetrahydrofuran

“…Einen einfachen Zugang zu den monomeren Bis(triisopropylsilylarsaniden) von Calcium (1) [18], Strontium (2) [18] [21,22]. Verbindungen dieses Typs sind dank ihrer leicht variierbaren lipophilen Hu È lle in herko È mmlichen organischen Solventien lo È slich.…”

“…Die Synthese von Triisopropylsilylarsan[19], Tetrakis(tetrahydrofuran)calcium-bis-(triisopropylsilylarsanid) (1) und Tetrakis(tetrahydrofuran)strontium-bis(triisopropylsilylarsanid) (2)[18] erfolgte entsprechend den Literaturvorschriften. Wie erwartet nimmt die Winkelung des As±M±As-Fragments in der Reihe von Calcium zum Barium hin zu.…”