Emergence of intense near-infrared photoluminescence by photoactivation of silver nanoclusters

Photoirradiation to a pyridine solution of Ag29 nanoclusters (NCs) with red photoluminescence (PL) at 680 nm activated intense PL in the near infrared (NIR) region, giving a PL quantum yield...

Hydrogen-bonding-directed helical nanofibers in a polythiophene-based all-conjugated diblock copolymer

Helical nanofibers with a large aspect ratio were crafted from an achiral all-conjugated diblock copolymer, P3HT-b-P3HHT, in an aged pyridine solution. Such helical nanofibers exhibit superior mechanical properties and charge transport properties.

Synthesis of an iridium porphyrin amido complex

A synthetic route for iridium porphyrin amido complexes has been established. Treatment of a THF solution of Ir(ttp)(CO)Cl (1) (ttp = 5,10,15,20-tetrakis(p-tolyl)porphyrinato dianion) with an aqueous mixture of NaOH and NaBH4, followed by 2-iodoethanol leads to the clean formation of the β-hydroxyethyl complex Ir(ttp)(C2H4OH) (2) in 92% yield. Heating a pyridine solution of complex 2 in the presence of ca. 5–10 equiv. of phthalimide (HNC8H4O2; HPhth) leads to the formation of Ir(ttp)(C5H5N)(CH2CH2Phth) (3). The replacement of pyridine by THF as the reaction solvent leads to the formation of the THF adduct Ir(ttp)(THF)(Phth) (4), which has been characterized spectroscopically. Heating a solution of 4 in pyridine leads to the formation of Ir(ttp)(C5H5N)(Phth) (5), which has been isolated in 72% yield. Complexes 3 and 5 have been characterized by X-ray crystallographic studies. Complexes 4 and 5 are rare examples of monomeric late transition metal-amido complexes and are the first examples of iridium-amido complexes featuring a porphyrin as a supporting ligand.

Dehydration of water/pyridine mixtures by pervaporation using cellulose acetate/ polyacrylonitrile blend membrane

Cellulose acetate/ polyacrylonitrile (CA/PAN) membranes were prepared and used to separate pyridine / water mixtures by pervaporation. The membranes were characterized through SEM. The effects of feed concentration, operation temperature and downstream pressure on the separation performance were evaluated. Experimental results indicated the increase of operation temperature could raise the permeation flux and the separation factor, while increasing feed concentration and downstream pressure would raise the separation factor and decrease the permeation flux. Under the conditions that pyridine solution was 99 wt.%, operation temperature was 323 K and downstream pressure was 20 mmHg, the CA/PAN blend membrane showed its best separation performance that the permeation flux was 56 · g · m−2 h−1 and the separation factor was 182.