title: DABCO-directed self-assembly of bisporphyrins (DABCO=1,4-diazabicyclo[2.2.2]octane).
abstract: 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.
authors.affiliation: 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
authors.forename: Pablo
authors.initials: P
authors.lastname: Ballester
authors.forename: Antoni
authors.initials: A
authors.lastname: Costa
authors.forename: Ana M
authors.initials: AM
authors.lastname: Castilla
authors.forename: Pere M
authors.initials: PM
authors.lastname: Deyà
authors.forename: Antonio
authors.initials: A
authors.lastname: Frontera
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Gomila
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Hunter
mesh_terms: 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*
chemical_list: D009942:Organometallic Compounds; D010795:Phthalic Acids; D010879:Piperazines; D011166:Porphyrins; C059768:isophthalate; D015032:Zinc; C007306:triethylenediamine