TY - JOUR
T1 - Synthesis, structural studies and photochemistry of cobalt(iii) complexes of anthracenylcyclam macrocycles
AU - Funston, Alison M.
AU - Ghiggino, Kenneth P.
AU - Grannas, Martin J.
AU - David McFadyen, W.
AU - Tregloan, Peter A.
PY - 2003/9/25
Y1 - 2003/9/25
N2 - This work reports the syntheses, structures and some photochemistry in DMF of the cobalt complexes trans-[CoIII(2)Cl2]Cl·0.5CH3OH and trans-[CoIII(3)Cl2]Cl·4H2O, where 2 is 6-(anthracen-9-ylmethyl)-1,4,8,11-tetraazacyclotetradecane-5,7-dione and 3 is 6-(anthracen-9-ylmethyl)-1,4,8,11-tetraazacyclotetradecane. In the preparation of the macrocyclic ligand, 3, the formation of a polycyclic bis(aminal) intermediate and its subsequent acid hydrolysis to 3 is a cleaner route than the traditional procedure in which the analogous dioxocyclam 2 is reduced with borane reagents. The crystal structure of trans-[CoIII(3)Cl2]Cl·4H2O shows that the macrocycle adopts the trans-III conformation, in which the anthracene moiety is extended away from the cobalt ion and the anthracene to Co separation is 7.22 Å. For the related complex trans-[CoIII(2)Cl2]Cl·0.5CH3OH, however, the anthracene is bent over the highly conjugated tetracycle and significant interactions between the anthracene and the complex occur. A novel new complex, trans-[Co(12)Cl2] (where 12 is 5,7-hydroxy-6-oxo-1,4,8,11-tetraazacyclotetradecane-4,7-diene) which is a degradation product of the complex trans-[CoIII(2)Cl2]Cl is also reported.
AB - This work reports the syntheses, structures and some photochemistry in DMF of the cobalt complexes trans-[CoIII(2)Cl2]Cl·0.5CH3OH and trans-[CoIII(3)Cl2]Cl·4H2O, where 2 is 6-(anthracen-9-ylmethyl)-1,4,8,11-tetraazacyclotetradecane-5,7-dione and 3 is 6-(anthracen-9-ylmethyl)-1,4,8,11-tetraazacyclotetradecane. In the preparation of the macrocyclic ligand, 3, the formation of a polycyclic bis(aminal) intermediate and its subsequent acid hydrolysis to 3 is a cleaner route than the traditional procedure in which the analogous dioxocyclam 2 is reduced with borane reagents. The crystal structure of trans-[CoIII(3)Cl2]Cl·4H2O shows that the macrocycle adopts the trans-III conformation, in which the anthracene moiety is extended away from the cobalt ion and the anthracene to Co separation is 7.22 Å. For the related complex trans-[CoIII(2)Cl2]Cl·0.5CH3OH, however, the anthracene is bent over the highly conjugated tetracycle and significant interactions between the anthracene and the complex occur. A novel new complex, trans-[Co(12)Cl2] (where 12 is 5,7-hydroxy-6-oxo-1,4,8,11-tetraazacyclotetradecane-4,7-diene) which is a degradation product of the complex trans-[CoIII(2)Cl2]Cl is also reported.
KW - Cobalt
KW - Macrocycles
KW - Photochemistry
KW - Structual studies
KW - X-ray diffraction, X-ray powder diffraction
UR - http://www.scopus.com/inward/record.url?scp=0142196628&partnerID=8YFLogxK
U2 - 10.1039/b305773a
DO - 10.1039/b305773a
M3 - Article
AN - SCOPUS:0142196628
VL - 3
SP - 3704
EP - 3712
JO - Dalton Transactions
JF - Dalton Transactions
SN - 1477-9226
IS - 19
ER -