Preparation and self-assembly of chiral porphyrin diads on the gold electrodes of quartz crystal microbalances: a novel potential approach to the development of enantioselective chemical sensors.
Porphyrin diad 1 was synthesized by reaction of the acyl chloride of porphyrin 2 and trans-1,2-dithiane-4,5-diol. The Co complex of this diad was studied as a potential enantioselective receptor for chiral recognition in solution and in the solid state. In solution both enantiomers of limonene induce significant changes in the visible and circular dichroism (CD) spectra of [Co2(1)], while a different behavior is observed in the case of the enantiomeric pair of trans-1,2-diaminocyclohexane. A different efficiency of [Co2(1)] chiral recognition is obtained for these compounds, with a remarkable degree of enantiodiscrimination observed in the case of limonene. Self-assembled monolayers of [Co2(1)] were deposited onto the gold electrodes of quartz crystal microbalances to be used as sensing materials of nanogravimetric sensors operating in the gas phase. The enantiodiscrimination properties of these sensors towards the enantiomeric pairs of chiral analytes have been studied. While in the case of analytes bearing donor ligand atoms we did not observe a remarkable enantioselectivity, a significant degree of chiral discrimination was observed in the case of limonene; this result is particularly encouraging for the potential development of enantioselective chemical sensors for use in an array configuration.
Dipartimento di Scienze e Tecnologie Chimiche Università di Roma Tor Vergata Via della Ricerca Scientifica, 00133 Rome, Italy. roberto.paolesse@uniroma2.it
Roberto
R
Paolesse
Donato
D
Monti
Laura
L
La Monica
Mariano
M
Venanzi
Antonella
A
Froiio
Sara
S
Nardis
Corrado
C
Di Natale
Eugenio
E
Martinelli
Arnaldo
A
D'Amico
D003035:Cobalt / Q000737:chemistry; D003460:Crystallization; D053138:Cyclohexenes; D004809:Ephedrine / Q000032:analysis / Q000737:chemistry; D004867:Equipment Design; D006046:Gold; D000077222:Limonene; D008610:Menthol / Q000032:analysis / Q000737:chemistry; D008839:Microelectrodes / Q000592:standards*; D009862:Online Systems; D009942:Organometallic Compounds / Q000032:analysis* / Q000737:chemistry; D011166:Porphyrins / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D013729:Terpenes / Q000032:analysis / Q000737:chemistry
D053138:Cyclohexenes; D009942:Organometallic Compounds; D011166:Porphyrins; D013729:Terpenes; D008610:Menthol; D003035:Cobalt; D006046:Gold; D000077222:Limonene; D004809:Ephedrine