Pentacarbonyl(tetrafluoroborato)rhenium reacts with trimethyl-(1-propynyl)stannane to give (OC) 5 Re–C C–CH 3 ( 1 ), with ethynyltrimethylsilane the σ,π-ethynide bridged complex [(OC) 5 Re(μ-η 1 ,η 2 -C CH)Re(CO) 5 ] + BF – 4 ( 2 ) is formed. From 2 and ...
已知全集 ,集合 , ,且AÜð U B ,求实数 a 的取值范围. 扫码下载作业帮拍照答疑一拍即得 答案解析 查看更多优质解析 举报 实数a 的取值范围是(﹣∞,1)∪(4,+∞). ①若 Æ,则ð U B =R,AÜð U B 成立,此时有 ,得 .②若 ≠Æ,则 , ,此时ð U B = 要使AÜð U ......
Die Chelatbildung von N-Tris(2-aminoethyl)amin-N′,N′,N″,N″,N‴,N‴-hexaessigsäure (H 6 TTAHA) und N-(Pyrid-2-yl-methyl)ethylendiamin-N,N′,N′-triessigsäure (H 3 PEDTA) mit Gadolinium(III) – Synthesen, Komplexstabilität und NMR-Relaxivität †...
(CH 3 ) 2 C 2 N 2 S 3 crystallizes with Z = 4 in the monoclinic space group P2 1 /c with cell dimensions a = 7.661(4) Å, b = 11.675(5) Å, c = 9.549(5) Å, β = 116.7(3)·. The crystal and molecular structure has been determined from single X-ray data at 20...