Exploring the nitrosyl-approach: “Re(CO)2(NO)”- and “Tc(CO)2(NO)”-complexes provide new pathways for bioorganometallic chemistry
摘要:
Nitrosylation reactions are rare in the context of low valent Re(l)- and Tc(l)-tricarbonyl complexes so far. We herein de:scribe a method for the conversion of a "M(CO)(3)-Moiety" (M = Re, Tc) into a dicarbonyl-nitrosyl Moiety "M(CO)(2)NO", the synthesis of important precursor complexes and intermediates and possible applications for this new kind of Re- and Tc-chemistry.The behavior of the complex [ReCl3](CO)(2)(NO)](-) in water was studied in detail and compared to that of [ReCl3(CO)(3)](2-). Contrary to the conversion of [ReCl3(CO)(3)](2-) to the mixed aquo-carbonyl complex [Re(OH2)(3)(CO)(3)](+) in water, one chloride remains initially bound to the metal center in the dicarbonyl-nitrosyl complex, making [ReCl(OH2)(2)(CO)(2)(NO)](+) the main species for further reactions. In this context, we isolated and characterized the complex [Re(mu3-O)(CO)(2)(NO)](4). Examples of complexes with different bi- and tridentate ligands based on ReCl3(CO)(2)(NO)](-) are discussed.For the development of potential new radiopharmaceuticals we also adapted the nitrosylation technique to the n.c.a. level with Tc-99m. [Tc-99m(OH2)(3)(CO)(3)](+) served as starting material to form a Tc-99m(CO)(2)(NO)-core. Labelling reactions with ligands such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA) and diethylenetriamine pentaacetic acid (DTPA) were performed, resulting in the complexes [Tc-99m(IDA)(CO)(2)(NO)], [Tc-99m(NTA)(CO)(2)(NO)] and [Tc-99m(DTPA)(CO)(2)(NO)]. In this way, the "nitrosyl-approach" adds a new and challenging synthetic too] to the already established organometallic chemistry of Re- and Tc-tricarbonyl complexes. (C) 2004 Elsevier B.V. All rights reserved.
Exploring the nitrosyl-approach: “Re(CO)2(NO)”- and “Tc(CO)2(NO)”-complexes provide new pathways for bioorganometallic chemistry
摘要:
Nitrosylation reactions are rare in the context of low valent Re(l)- and Tc(l)-tricarbonyl complexes so far. We herein de:scribe a method for the conversion of a "M(CO)(3)-Moiety" (M = Re, Tc) into a dicarbonyl-nitrosyl Moiety "M(CO)(2)NO", the synthesis of important precursor complexes and intermediates and possible applications for this new kind of Re- and Tc-chemistry.The behavior of the complex [ReCl3](CO)(2)(NO)](-) in water was studied in detail and compared to that of [ReCl3(CO)(3)](2-). Contrary to the conversion of [ReCl3(CO)(3)](2-) to the mixed aquo-carbonyl complex [Re(OH2)(3)(CO)(3)](+) in water, one chloride remains initially bound to the metal center in the dicarbonyl-nitrosyl complex, making [ReCl(OH2)(2)(CO)(2)(NO)](+) the main species for further reactions. In this context, we isolated and characterized the complex [Re(mu3-O)(CO)(2)(NO)](4). Examples of complexes with different bi- and tridentate ligands based on ReCl3(CO)(2)(NO)](-) are discussed.For the development of potential new radiopharmaceuticals we also adapted the nitrosylation technique to the n.c.a. level with Tc-99m. [Tc-99m(OH2)(3)(CO)(3)](+) served as starting material to form a Tc-99m(CO)(2)(NO)-core. Labelling reactions with ligands such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA) and diethylenetriamine pentaacetic acid (DTPA) were performed, resulting in the complexes [Tc-99m(IDA)(CO)(2)(NO)], [Tc-99m(NTA)(CO)(2)(NO)] and [Tc-99m(DTPA)(CO)(2)(NO)]. In this way, the "nitrosyl-approach" adds a new and challenging synthetic too] to the already established organometallic chemistry of Re- and Tc-tricarbonyl complexes. (C) 2004 Elsevier B.V. All rights reserved.