Strontium- und Barium-bis[N,N′ -bis(trimethylsilyl)benzamidinate] aus der Additionsreaktion der Erdalkalimetall-bis[bis(trimethylsilyl)amide] mit Benzonitril

Strontium and Barium Bis[N,N′-bis(trimethylsilyl)benzamidinates] from the Addition Reaction of the Alkaline Earth Metal Bis[bis(trimethylsilyl)amides] and Benzonitrile The reaction of strontium bis[bis trimethylsilyl)amide] with benzonitrile yields strontium bis[N,N′- bis(trimethylsilyl)benzamidinate] · 2THF, which crystallizes in the orthorhombic space group Pbcn (a = 1845.4(3); b = 131 1,3(2); c = 1838,(3) pm; Z = 4). During the similar reaction of barium bis[bis(trimethylsilyl)amide] with benzonitrile the benzonitrile adduct barium bis[N,N′-bis(trimethylsilyl)benzamidinate] · 2 THF · benzonitrile is formed. After the addition of diphenylacetylene to the strontium di(benzamidinate) in diglyme a clathrate of the composition strontium bis[N,N′-bis(trimethylsilyl)benzamidinate] · diglyme · diphenylacetylene could be isolated; the spectroscopic data as well as the X-ray structure (monoclinic, C2/c, a = 1492.2(2); b = 1539.1(2); c = 2337.8(3)pm; Z = 4) confirm the isolated appearance of the acetylene molecule without interaction to the metal center in solution and in the solid state, respectively.     

Hexanuclear Wheel‐Shaped Lithium N‐(2,6‐Diisopropylphenyl)‐N′‐(2‐pyridylethyl)benzamidinate

Lithiation of N‐(2,6‐diisopropylphenyl)‐N′‐(2‐pyridylethyl)benzamidine ( 1 ) with LiN(SiMe₃)₂ in a solvent mixture of toluene and TMEDA yields hexameric lithium N‐(2,6‐diisopropylphenyl)‐N′‐(2‐pyridylethyl)benzamidinate ( 2 ), which can be purified by recrystallization from a solvent mixture of toluene and THF. The three‐coordinate lithium ions have T‐shaped coordination spheres. The negative charge is delocalized within the 1,3‐diazaallylic system, which adopts a (syn‐Z)‐arrangement.