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Inclusion complexes of benzo- and dithiabenzocrown ether functionalized monopyrrolotetrathiafulvalene (MPTTF) molecules were formed with Li+@C60 (1.Li+@C60 and 2.Li+@C60). The strong complexation has been quantified by high binding constants that exceed 106m-1 obtained by UV/Vis titrations in benzonitrile (PhCN) at room temperature. On the basis of DFT studies at the B3LYP/6-311G(d,p) level, the orbital interactions between the crown ether moieties and the π surface of the fullerene together with the endohedral Li+ have a crucial role in robust complex formation. Interestingly, complexation of Li+@C60 with crown ethers accelerates the intersystem crossing upon photoexcitation of the complex, thereby yielding 3(Li+@C60)*, when no charge separation by means of 1Li+@C60* occurs. Photoinduced charge separation by means of 3Li+@C60* with lifetimes of 135 and 120 μs for 1.Li+@C60 and 2.Li+@C60, respectively, and quantum yields of 0.82 in PhCN have been observed by utilizing time-resolved transient absorption spectroscopy and then confirmed by electron paramagnetic resonance measurements at 4 K. The difference in crown ether structures affects the binding constant and the rates of photoinduced electron-transfer events in the corresponding complex. [ABSTRACT FROM AUTHOR]

Three new hybrid gated mesoporous materials ( SN3-1, SNH2-2, and SN3-3) loaded with the dye [Ru(bipy)3]2+ (bipy=bipyridine) and capped with different tetrathiafulvalene (TTF) derivatives (having different sizes and shapes and incorporating different numbers of sulfur atoms) have been prepared. The materials SN3-1 and SN3-3 are functionalized on their external surfaces with the TTF derivatives 1 and 3, respectively, which were attached by employing the 'click' chemistry reaction, whereas SNH2-2 incorporates the TTF derivative 2, which was anchored to the solid through an amidation reaction. The final gated materials have been characterized by standard techniques. Suspensions of these solids in acetonitrile showed 'zero release', most likely because of the formation of dense TTF networks around the pore outlets. The release of the entrapped [Ru(bipy)3]2+ dye from SN3-1, SNH2-2, and SN3-3 was studied in the presence of selected explosives (Tetryl, TNT, TNB, DNT, RDX, PETN, PA, and TATP). SNH2-2 showed a fairly selective response to Tetryl, whereas for SN3-1 and SN3-3 dye release was found to occur with Tetryl, TNT, and TNB. The uncapping process in the three materials can be ascribed to the formation of charge-transfer complexes between the electron-donating TTF units and the electron-accepting nitroaromatic explosives. Finally, solids SNH2-2 and SN3-1 have been tested for Tetryl detection in soil with good results, pointing toward a possible use of these or similar hybrid capped materials as probes for the selective chromo-fluorogenic detection of nitroaromatic explosives. [ABSTRACT FROM AUTHOR]

The electron-donor and unique redox properties of the tetrathiafulvalene (TTF, 1) moiety have led to diverse applications in many areas of chemistry. Monopyrrolotetrathiafulvalenes (MPTTFs, 4) and bispyrrolotetrathiafulvalenes (BPTTFs, 5) are useful structural motifs and have found widespread use in fields such as supramolecular chemistry and molecular electronics. Protocols enabling the synthesis of functionalised MPTTFs and BPTTFs are therefore of broad interest. Herein, we present the synthesis of a range of functionalised MPTTF and BPTTF species. Firstly, the large-scale preparation of the precursor species N-tosyl-(1,3)-dithiolo[4,5-c]pyrrole-2-one (6) is described, as well as the synthesis of the analogue N-tosyl-4,6-dimethyl-(1,3)-dithiolo[4,5-c]pyrrole-2-one (7). Thereafter, we show how 6 and 7 can be used to prepare BPTTFs using homocoupling reactions and functionalised MPTTFs using cross-coupling reactions with a variety of 1,3-dithiole-2-thiones (19). Subsequently, the incorporation of more complex functionality is discussed. We show how the 2-cyanoethyl protecting group can be used to afford MPTTFs functionalised with thioethers, exemplified by a series of ethylene glycol derivatives. Additionally, the merits of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as an alternative to the most common deprotecting agent, CsOH·H2O are discussed. Finally, we show how a copper-mediated Ullman-type reaction can be applied to the N-arylation of MPTTFs and BPTTFs using a variety of aryl halides.

Inclusion complexes of benzo- and dithiabenzo-crown ether functionalized monopyrrolotetrathiafulvalene (MPTTF) molecules were formed with Li(+)@C60(1⋅Li(+)@C60 and 2⋅Li(+)@C60). The strong complexation has been quantified by high binding constants that exceed 10(6) M(-1) obtained by UV/Vis titrations in benzonitrile (PhCN) at room temperature. On the basis of DFT studies at the B3LYP/6-311G(d,p) level, the orbital interactions between the crown ether moieties and the π surface of the fullerene together with the endohedral Li(+) have a crucial role in robust complex formation. Interestingly, complexation of Li(+)@C60 with crown ethers accelerates the intersystem crossing upon photoexcitation of the complex, thereby yielding (3)(Li(+)@C60)*, when no charge separation by means of (1)Li(+)@C60* occurs. Photoinduced charge separation by means of (3)Li(+)@C60* with lifetimes of 135 and 120 μs for 1⋅Li(+)@C60 and 2⋅Li(+)@C60, respectively, and quantum yields of 0.82 in PhCN have been observed by utilizing time-resolved transient absorption spectroscopy and then confirmed by electron paramagnetic resonance measurements at 4 K. The difference in crown ether structures affects the binding constant and the rates of photoinduced electron-transfer events in the corresponding complex., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Three new hybrid gated mesoporous materials (SN3 -1, SNH2 -2, and SN3 -3) loaded with the dye [Ru(bipy)3 ](2+) (bipy=bipyridine) and capped with different tetrathiafulvalene (TTF) derivatives (having different sizes and shapes and incorporating different numbers of sulfur atoms) have been prepared. The materials SN3 -1 and SN3 -3 are functionalized on their external surfaces with the TTF derivatives 1 and 3, respectively, which were attached by employing the "click" chemistry reaction, whereas SNH2 -2 incorporates the TTF derivative 2, which was anchored to the solid through an amidation reaction. The final gated materials have been characterized by standard techniques. Suspensions of these solids in acetonitrile showed "zero release", most likely because of the formation of dense TTF networks around the pore outlets. The release of the entrapped [Ru(bipy)3 ](2+) dye from SN3 -1, SNH2 -2, and SN3 -3 was studied in the presence of selected explosives (Tetryl, TNT, TNB, DNT, RDX, PETN, PA, and TATP). SNH2 -2 showed a fairly selective response to Tetryl, whereas for SN3 -1 and SN3 -3 dye release was found to occur with Tetryl, TNT, and TNB. The uncapping process in the three materials can be ascribed to the formation of charge-transfer complexes between the electron-donating TTF units and the electron-accepting nitroaromatic explosives. Finally, solids SNH2 -2 and SN3 -1 have been tested for Tetryl detection in soil with good results, pointing toward a possible use of these or similar hybrid capped materials as probes for the selective chromo-fluorogenic detection of nitroaromatic explosives., (Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)