title: Al3+ induced planarization, conformational arrest and metallochromic shift in a pyrimidine dione dye: insight from integrated hybrid quantum-classical calculations.
abstract: In order to explore the possibilities of simulating metallochromism by modern molecular modeling, we apply a sequential hybrid quantum-classical approach to a prototype metallochromic system-the Al(3+) ion and pyrimidinedione (PY) dye complex. The complex shows several structural features with relevance for the metallochromism: the PY dye exhibits conformers with dynamical transitions between twisted structures, which are inhibited by the addition of the metal ion leading to planarization and a conformational arrest: the Al(3+) ion behaves like a structure-modifier for both intra and intermolecular degrees of freedom and with respect to the intermolecular solvation shell structure. The sequential approach that we have employed uses DFT/MM molecular dynamics for structure modeling and TDDFT/PCM for property modeling. The computed metallochromic shift between PY and the Al(PY)(3+) complex in DMSO solvent is obtained in excellent agreement with experiment. The results infer optimism for future use of such modeling techniques to design metallochromic indicators.
authors.affiliation: Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, SE-10691 Stockholm, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Selvaraj
authors.forename: N Arul
authors.initials: NA
authors.lastname: Murugan
authors.forename: H
authors.initials: H
authors.lastname: Agren
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D008968:Molecular Conformation; D011743:Pyrimidines / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D004396:Coloring Agents; D056831:Coordination Complexes; D007477:Ions; D011743:Pyrimidines; D000535:Aluminum; C030986:pyrimidine