Effect of Side Chain Substituent Volume on Thermoelectric Properties of IDT-Based Conjugated Polymers.

A p-type thermoelectric conjugated polymer based on indacenodithiophene and benzothiadiazole is designed and synthesized by replacing normal aliphatic side chains (P1) with conjugated aromatic benzene substituents (P2). The introduced bulky substituent on P2 is detrimental to form the intensified packing of polymers, therefore, it hinders the efficient transporting of the charge carriers, eventually resulting in a lower conductivity compared to that of the polymers bearing aliphatic side chains (P1). These results reveal that the modification of side chains on conjugated polymers is crucial to rationally designed thermoelectric polymers with high performance.

5,11,17,23-Tetra-kis(1,1-di-methyl-eth-yl)-26,28-di-hydroxy-calix[4]arene-25,27-mono-thia-crown-3.

The title calix[4]arene compound [systematic name: 3,9,15,34-tetra-tert-butyl-19,29-dioxa-24-thia-hexa-cyclo-[15.13.7.1(7,11).1(32,36).0(5,30).0(13,18)]nona-triaconta-1(30),2,4,7,9,11(39),13,15,17,32,34,36(38)-dodeca-ene-38,39-diol], C52H70O4S, displays a cone-like conformation, the opposite arene rings bridged by the mono-thia-crown-3 unit are nearly parallel [dihedral angle = 16.01 (18)°], whereas the other opposite arene rings are twisted to each other at an angle of 74.41 (17)°. Intra-molecular O-H⋯O hydrogen bonds help to stabilize the mol-ecular structure. In the crystal, a C-H⋯π inter-action occurs. One of the tert-butyl groups is disordered over two sets of sites with a site-occupancy ratio of 0.70:0.30.

Bifunctional fluoroionphore-ionic liquid hybrid for toxic heavy metal ions: improving its performance via the synergistic extraction strategy.

Several heavy metal ions (HMIs), such as Cd(2+), Pb(2+), and Hg(2+), are highly toxic even at very low concentrations. Although a large number of fluoroionphores have been synthesized for HMIs, only a few of them show detection limits that are below the maximum contamination levels in drinking water (usually in the nM range), and few of them can simultaneously detect and remove HMIs. In this work, we report a new fluoroionphore-ionic liquid hybrid-based strategy to improve the performance of classic fluoroionphores via a synergistic extraction effect and realize simultaneous instrument-free detection and removal of HMIs. As a proof-of-concept, Hg(2+) was chosen as a model HMI, and a rhodamine thiospirolactam was chosen as a model fluoroionphore to construct bifunctional fluoroionphore-ionic liquid hybrid 1. The new sensing system could provide obviously improved sensitivity by simply increasing the aqueous-to-ionic liquid phase volume ratio to 10:1, resulting in a detection limit of 800 pM for Hg(2+), and afford extraction efficiencies larger than 99% for Hg(2+). The novel strategy provides a general platform for highly sensitive detection and removal of various HMIs in aqueous samples and holds promise for environmental and biomedical applications.

Cationic recognition by tert-butylcalix[4]arene-functionalized nanoprobes.

A nanoparticle-based strategy has been demonstrated using structurally-tailored tert-butylcalixarenes immobilized on gold nanoparticles to tune the guest access to the calixarene cone cavity for cationic recognition. This strategy exploits the interparticle charge-induced aggregation upon selective capture of metal cations into the nanoparticle-immobilized tert-butylcalixarenes, which produces calorimetric changes for the detection. A possible pathway for the binding of M(n+) into the t-BCA structure and the interparticle interaction is proposed for the formation of an electric double layer inducing the interparticle association responsible for the red-shifted surface plasmon resonance band of the nanoparticles. The value of this class of calorimetric nanoprobes will be in the area of designing advanced host-guest probes using a variety of calixarene ligands for ionic recognition in a simplistic detection format.

Clicking fluoroionophores onto mesoporous silicas: a universal strategy toward efficient fluorescent surface sensors for metal ions.

Mesoporous SBA-15 silica is an excellent support for constructing fluorescent surface sensors. In this letter, we reported a two-step surface reaction involved strategy to construct efficient fluorescent surface sensors for metal ions by clicking fluoroionophores onto azide-functionalized SBA-15. Our experimental results indicate that such a strategy exhibits an obviously higher loading efficiency within commercial SBA-15 than a previously reported strategy. As a proof-of-concept, a newly designed alkyne-functionalized Hg(2+) fluoroionophore was grafted onto SBA-15 to form a fluorescent Hg(2+) surface sensor. It shows improved sensitivity and selectivity than the fluoroionophore itself working in the solution phase with a detection limit of 2.0 x 10(-8) M for Hg(2+).