Experimental and Computational Studies of Intracomplex Reactions in Mg+(Primary, Secondary Alkylamine) Complexes Induced by Photoexcitation of Mg+

✍ Scribed by Haichuan Liu; Yihua Hu; Shihe Yang; Wenyue Guo; Xiaoqing Lu; Lianming Zhao

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 355 KB
• Volume: 11
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.200401325

✦ Synopsis

Abstract

We report herein a comprehensive study of photoinduced reactions in complexes of Mg^+^ with primary (n‐propyl‐ and isopropylamine) and secondary amines (dipropyl‐ and diisopropylamine) in the spectral range of 230–440 nm. Similar to the methyl‐ and ethylamine complexes studied previously, NH bond activation of these complexes is very unfavorable. Instead, the C^α^C, CN, and C^α^H bond‐cleavage photoproducts are observed after photoexcitation of the Mg^+^ complexes (3^2^P←3^2^S). For Mg^+^(primary amine) complexes, for example, Mg^+^NH~2~CH~2~CH~2~CH~3~, and Mg^+^NH~2~CH(CH~3~)~2~, the photoproducts resulting from C^α^C rupture prevail after P~z~ and charge‐transfer excitations, whereas the Mg^+^ photofragment is predominant upon P~x,y~ excitation. However, with further N‐alkyl substitution, as in Mg^+^(secondary amine) complexes, for example, Mg^+^NH(CH~2~CH~2~CH~3~)~2~ and Mg^+^NH[CH(CH~3~)~2~]~2~, a novel intracomplex CC coupling photoreaction dominates on P~x,y~ excitation of Mg^+^, which is believed to arise from Mg^+^* insertion into the CN bond. With P~z~ and charge‐transfer excitation, the MgR elimination photoproducts, arising from C^α^C bond cleavage, predominate. The energetics and possible mechanisms of the intracomplex photoreactions are analyzed in detail with the help of extensive quantum mechanics calculations.