DABCO-directed self-assembly of bisporphyrins (DABCO=1,4-diazabicyclo[2.2.2]octane).
Three isomeric zinc bisporphyrins have been prepared by covalently linking together two aminoporphyrins with an isophthalic acid derivative. The porphyrins differ in the substitution pattern on the meso phenyl groups, that is, ortho, meta, or para. Titrations carried out by UV-visible and 1H NMR spectroscopy have been used to map out the stabilities and the stoichiometries of the complexes formed with 1,4-diazabicyclo[2.2.2]octane (DABCO) in chloroform. The ortho- and meta-substituted bisporphyrins form 1:1 intramolecular sandwich complexes. The para-substituted bisporphyrin cannot adopt the cofacial conformation required for this type of complex and forms a higher order 2:2 intermolecular assembly, which is stable over a wide range of DABCO concentrations.
Ballester
Pablo
P
Institució Catalana de Recerca i Estudis Avançats (ICREA) and Institut Català d'Investigació Química (ICIQ), Avgda. Països Catalans, s/n, 43007-Tarragona, Spain. pballester@iciq.es
Costa
Antoni
A
Castilla
Ana M
AM
Deyà
Pere M
PM
Frontera
Antonio
A
Gomila
Rosa M
RM
Hunter
Christopher A
CA
D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010795:Phthalic Acids / Q000737:chemistry; D010879:Piperazines / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D017186:Titrimetry; D015032:Zinc / Q000737:chemistry*
D009942:Organometallic Compounds; D010795:Phthalic Acids; D010879:Piperazines; D011166:Porphyrins; C059768:isophthalate; D015032:Zinc; C007306:triethylenediamine