title: Resonant-convergent PCM response theory for the calculation of second harmonic generation in makaluvamines A-V: pyrroloiminoquinone marine natural products from poriferans of genus Zyzzya.
abstract: The first-order hyperpolarizability, β, has been calculated for a group of marine natural products, the makaluvamines. These compounds possess a common cationic pyrroloiminoquinone structure that is substituted to varying degrees. Calculations at the MP2 level indicate that makaluvamines possessing phenolic side chains conjugated with the pyrroloiminoquinone moiety display large β values, while breaking this conjugation leads to a dramatic decrease in the calculated hyperpolarizability. This is consistent with a charge-transfer donor-π-acceptor (D-π-A) structure type, characteristic of nonlinear optical chromophores. Dynamic hyperpolarizabilities calculated using resonance-convergent time-dependent density functional theory coupled to polarizable continuum model (PCM) solvation suggest that significant resonance enhancement effects can be expected for incident radiation with wavelengths around 800 nm. The results of the current work suggest that the pyrroloiminoquinone moiety represents a potentially useful new chromophore subunit, in particular for the development of molecular probes for biological imaging. The introduction of solvent-solute interactions in the theory is conventionally made in a density matrix formalism, and the present work will provide detailed account of the approximations that need to be introduced in wave function theory and our program implementation. The program implementation as such is achieved by a mere combination of existing modules from previous developments, and it is here only briefly reviewed.
authors.affiliation: †Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Department of Materials Physics, University of the Basque Country, CFM CSIC-UPV/EHU-MPC and DIPC, Avenida de Tolosa 72, E-20018 Donostia, Spain.|‡Centre for Computational Physics, Department of Physics, University of Coimbra, Rua Larga, 3004-516 Coimbra, Portugal.
authors.forename: Bruce F
authors.initials: BF
authors.lastname: Milne
authors.affiliation: §Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping, Sweden.
authors.forename: Patrick
authors.initials: P
authors.lastname: Norman
mesh_terms: D000818:Animals; D001688:Biological Products / Q000737:chemistry*; D003198:Computer Simulation; D008956:Models, Chemical; D015394:Molecular Structure; D017711:Nonlinear Dynamics; D009792:Oceans and Seas; D055668:Photochemical Processes; D011161:Porifera / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D047608:Pyrroloiminoquinones / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry
chemical_list: D001688:Biological Products; D011758:Pyrroles; D047608:Pyrroloiminoquinones; D012997:Solvents