Three calix[4]pyrroles bearing m-orcinol-derived diether straps of different lengths on one side of the tetrapyrrolic core have been synthesized and characterized. Structural information for an analogous diester bridged strapped system reported previously (Yoon, D. W.; Hwang, H.; Lee, C. H. Angew. Chem., Int. Ed. Engl. 2002, 41, 1757-1759) is also provided as are bromide and chloride anion affinities for all four systems determined by Isothermal Titration Calorimetry (ITC) in acetonitrile. Although both sets of the strapped calix[4]pyrroles displayed enhanced affinities for chloride and bromide anion, differences were seen among the various receptors that support the conclusion that the anion binding ability of calixpyrrole-type systems can be effectively tuned by modifying the length and nature of the bridging straps. In the specific case of the diether systems, the largest chloride affinity was seen with the shortest strap, whereas the largest affinity for bromide anion was recorded in the case of the longest strap. On the basis of these findings, as well as supporting (1)H NMR spectroscopic studies, it is postulated that not only cavity size per se, but also the ability of the aryl portion of the strap to serve as a CH hydrogen bond donor site are important in regulating the observed anion affinities.

Light from confusion: A set of doubly N‐confused calix[6]phyrins bearing two coordination sites (NNNC,NNNC or NNNN,NNCC) were synthesized. Their bis‐PtII complexes exhibit near‐infrared emission around 1000 nm, which could make these compounds ideal for biological applications.

Pt(II) complex of meso-tetrakis(pentafluorophenyl) N-confused porphyrin (1-Pt) efficiently binds Cl(-), Br(-), and I(-) anions at the peripheral N-H, while deprotonation proceeds with F(-), H(2)PO(4)(-), and OH(-) in CH(2)Cl(2) solution; neutral and anionic structures of 1-Pt were characterized by single crystal X-ray diffraction analysis.

Triplet photosensitizers that generate singlet oxygen efficientlya re attractive for applications such as photodynamic therapy (PDT). Extending the absorption band to an ear-infrared (NIR) region (700 nm %)w ith reasonable photostability is one of the major demands in the rational design of such sensitizers. We herein prepared as eries of mono-and bis-palladium complexes (1-Pd-H 2 , 2-Pd-H 2 , 1-Pd-Pd,a nd 2-Pd-Pd)b ased on modified calix[6]phyrins as photosensitizers for singlet oxygen generation.T hese palladium complexes showed intense absorption profiles in the visible-to-NIR region (500-750nm) depending on the number of central metals. Upon photoirradiation in the presence of 1,5-dihydroxynaphthalene (DHN) as as ubstrate for reactiveo xygen species, the bis-palladium complexes generated singlet oxygen with high efficiency and excellent photostability.S inglet oxygen generation was confirmed from the characteristics pectral feature of the spin trapped complex in the EPR spectrum and the intact 1 O 2 emission at 1270 nm.