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| Names | |
|---|---|
| Preferred IUPAC name 1,4,8,11-Tetraazacyclotetradecane | |
| Identifiers | |
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3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider |
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| ECHA InfoCard | 100.005.491 |
| UNII | |
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| Properties | |
| C10H24N4 | |
| Molar mass | 200.330 g·mol−1 |
| Melting point | 185 to 188 °C (365 to 370 °F; 458 to 461 K) |
| 5 g/100 mL (20 °C) | |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Cyclam (1,4,8,11-tetraazacyclotetradecane) is anorganic compound with the formula (NHCH2CH2NHCH2CH2CH2)2. Classified as anaza-crown ether, it is a white solid that is soluble in water. As amacrocyclicligand, it binds strongly to many transition metalcations.[1] The compound was first prepared by the reaction of1,3-dibromopropane andethylenediamine.[2]
Cl2.png)
The compound features foursecondary amines. Its complexes therefore can exist as severaldiastereomers, depending on the relative orientation of the N–H centres. Its complexes feature alternating five- and six-membered chelate rings. The closely related ligandcyclen ((CH2CH2NH)4) forms only five-membered C2N2M chelate rings and tends not to form square-planar complexes.
Metal-cyclam complexes are prone to oxidative degradation, which is initiated by deprotonation of the secondary amine. This flaw led to the development of cyclam derivatives wherein the NH centres are replaced by tertiary amines. For example, the tetramethyl derivatives (tetramethylcyclam, tmc) are readily prepared by methylation usingformaldehyde and formic acid.[1] These oxidatively robust derivatives of cyclam have enabled a number ofmetal–O2 complexes.[4]
