abstract
A positively charged lamellar coordination polymer based on a flexible triphosphonic acid linker is reported. [Gd(H(4)nmp)(H2O)(2)]Cl center dot 2H(2)O (1) [H(6)nmp=nitrilotris(methylene-phosphonic acid)] was obtained by a one-pot approach by using water as a green solvent and by forcing the inclusion of additional acid sites by employing HCl in the synthesis. Compound 1 acts as a versatile heterogeneous acid catalyst with outstanding activity in organic reactions such as alcoholysis of styrene oxide, acetalization of benzaldehyde and cyclohexanaldehyde and ketalization of cyclohexanone. For all reaction systems, very high conversions were reached (92-97%) in only 15-30 min under mild conditions (35 degrees C, atmospheric pressure). The coordination polymer exhibits a protonic conductivity of 1.23 x 10(-5) Scm(-1) at 98% relative humidity and 40 degrees C.
keywords
METAL-ORGANIC FRAMEWORKS; ONE-POT ACETALIZATION; EFFICIENT ACETALIZATION; HETEROGENEOUS CATALYSTS; PROTON CONDUCTIVITY; LINKER SUBSTITUTION; MAGNETIC-PROPERTIES; DIMETHYL ACETALS; LEWIS ACIDITY; Y ZEOLITES
subject category
Chemistry
authors
Mendes, RF; Antunes, MM; Silva, P; Barbosa, P; Figueiredo, F; Linden, A; Rocha, J; Valente, AA; Paz, FAA
our authors
Groups
G1 - Porous Materials and Nanosystems
G3 - Electrochemical Materials, Interfaces and Coatings
G4 - Renewable Materials and Circular Economy
acknowledgements
Funding agencies and projects: We wish to thank Fundacao para a Ciencia e a Tecnologia (FCT, Portugal), the European Union, QREN, FEDER through Programa Operacional Factores de Competitividade (COMPETE) and CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. We also thank FCT for funding the R&D project FCOMP-01-0124-FEDER-041282 (Ref. FCT EXPL/CTM-NAN/0013/2013). Individual grants and scholarships: FCT is also gratefully acknowledged for the Ph.D. grants Nos. SFRH/BD/84231/2012 and SFRH/BD/46601/2008 (to R.F.M. and P.S., respectively), the post-doctoral grants Nos. SFRH/BPD/89068/2012 and SFRH/BPD/96665/2013 (to M.M.A. and P.B., respectively), and the Development grant No. IF/01174/2013 (to F.F.).