Combined NMR and DFT Study on the Complexation Behavior of Lappert鈥檚 Tin(II) Amide
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- 作者：Lies Broeckaert ; Jan Turek ; Roman Olejn铆k ; Ale拧 R暖啪i膷ka ; Monique Biesemans ; Paul Geerlings ; Rudolph Willem ; Frank De Proft
- 刊名：Organometallics
- 出版年：2013
- 出版时间：April 8, 2013
- 年：2013
- 卷：32
- 期：7
- 页码：2121-2134
- 全文大小：454K
- 年卷期：v.32,no.7(April 8, 2013)
- ISSN：1520-6041
文摘
The complexation chemistry of the stannylene Sn{N[Si(CH3)3]2}2, first reported by Lappert in the 1970s, was investigated by 119Sn NMR chemical shift measurements. To this end, experimental NMR data and theoretical density functional theory (DFT) calculations were combined to get an insight into the interaction between the stannylene and various solvent molecules with 蟽- and/or 蟺-coordinating power. Small variations in the measured 119Sn chemical shifts revealed a donor鈥揳cceptor interaction with the solvent molecules. In comparison to the noncoordinating solvent cyclohexane taken as a reference, a weak coordination was observed with aromatic solvent molecules (benzene and toluene) and a much stronger coordination with the 蟽-donors THF and pyridine. Pyridine was confirmed to be the strongest donor, as evidenced by its large upfield chemical shift 螖未(119Sn) of 635 ppm. The experimental chemical shifts were reproduced by DFT (NMR) calculations, demonstrating similar trends in the interaction strength with the 蟽- and 蟺-donors. The stannylene Sn{N[Si(CH3)3]2}2 showed the ability to react with Fe(CO)5 and Fe2(CO)9 in the molar ratio 1/1 to provide L2SnFe(CO)4 complexes. With a molar excess of Fe2(CO)9, L2Sn[Fe(CO)4]2 was generated irreversibly. Upon prolonged UV irradiation in the presence of W(CO)6, in the molar ratio 1/1, a mixture of L2SnW(CO)5 and two (L2Sn)2W(CO)4 complexes was generated.