Highly selective fluorescent recognition of phenyl amino alcohol based on ferrocenyl macrocyclic derivatives

Four ferrocenyl macrocyclic derivatives 3 and 4 containing anthracene fluorophores have been synthesized. The fluorescent properties of these receptors have been studied in three organic solvents, both in the absence and presence of phenyl amino alcohols. All receptors exhibit sensitive fluorescence response to l- or d-phenylglycinol, a strong emission band is produced due to the intermolecular exciplex between host and guest. These special phenomena were not observed when other species were used as the guests; such highly selective fluorescent response indicates that these receptors can easily discriminate phenylglycinol from other similar species. Solvent comparative experiments also indicate that acetonitrile is the most appropriate solvent to detect this fluorescent change. The intramolecular energy transfer between excited anthracene and ferrocene, and π–π stacking interaction between the aromatic rings play critical roles in this special fluorescence enhancement. Model calculations at DFT level further suggest the possible interaction modes, structures and relatively steric position between the host and guest also influence the optical response.

Graphical abstractFerrocenyl macrocyclic derivatives (3 and 4) containing anthracene fluorophores could discriminate phenylglycinol from other species through the obvious fluorescence enhancement and the occurrence of the strong emission band of intermolecular exciplex.Figure optionsDownload full-size imageDownload as PowerPoint slide

(R)-2-(tert-Butoxylcarbonyl)amino-N1,N5-bis(2-acetamidoethyl)pentanediamide-ferroceneC26H35N5O6Fe[α]D20=+41.4 (c 0.010, CHCl3)Source of chirality = d-glutamic acidAbsolute configuration: (R)

(R)-2-(tert-Butoxylcarbonyl)amino-N1,N5-bis(3-acetamidopropyl)pentanediamide-ferroceneC28H39N5O6Fe[α]D20=+17.3 (c 0.010, CHCl3)Source of chirality = d-glutamic acidAbsolute configuration: (R)

(R)-N1,N5-Bis(2-acetamidoethyl)-2-(anthracen-9-ylmethylamino)pentanediamide-ferroceneC36H37N5O4Fe[α]D20=+21.15 (c 0.010, CHCl3)Source of chirality = d-glutamic acidAbsolute configuration: (R)

(R)-N1,N5-Bis(3-acetamidopropyl)-2-(anthracen-9-ylmethylamino)pentanediamide-ferroceneC38H41N5O4Fe[α]D20=+8.8 (c 0.010, CHCl3)Source of chirality = d-glutamic acidAbsolute configuration: (R)

(R)-N1,N5-Bis(2-acetamidoethyl)-2-(3-(anthracen-9-ylmethyl)thioureido)pentanediamide-ferroceneC37H38N6O4SFe[α]D20=-33.56 (c 0.010, CHCl3)Source of chirality = d-glutamic acidAbsolute configuration: (R)

(R)-N1,N5-Bis(3-acetamidopropyl)-2-(3-(anthracen-9-ylmethyl)thioureido) pentanediamide-ferroceneC39H42N6O4SFe[α]D20=+4.25 (c 0.010, CHCl3)Source of chirality = d-glutamic acidAbsolute configuration: (R)

5,11,17,23-Tetra-4-tert-butyl-25,27-((R)-N1,N5-bis(2-(2-methoxylacetamido)ethyl)-2-(anthracen-9-ylmethylamino)pentanediamide)-26,28-dihydroxylcalix[4]areneC72H87N5O8[α]D20=+9.5 (c 0.010, CHCl3)Source of chirality = d-glutamic acidAbsolute configuration: (R)