Intramolecular halogen bonds between aryl halide donors and suitable acceptors, such as carbonyl or quinolinyl groups, held in proximity by 1,2-aryldiyne linkers, provide triangular structures in the solid state. Aryldiyne linkers provide a nearly ideal template for intramolecular halogen bonding as minor deviations from alkyne linearity can accommodate a variety of halogen bonding interactions, including O···Cl, O···Br, O···I, N···Br, and N···I. Halogen bond lengths for these units, observed by single crystal X-ray crystallography, range from 2.75 to 2.97 Å. Internal bond angles of the semirigid bridge between halogen bond donor and acceptor are responsive to changes in the identity of the halogen, the identity of the acceptor, and the electronic environment around the halogen, with the triangles retaining almost perfect co-planarity in even the most strained systems. Consistency between experimental results and structures predicted by M06-2X/6-31G* calculations demonstrates the efficacy of this computational method for modeling halogen-bonded structures of this type.

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The effective conjugation of ortho and ortho-alt-para-arylene ethynylenes, with appropriately positioned pyridine and pyrazine heterocycles, increases upon binding to Ag(I) and Pd(II) cations. Significant bathochromic shifts in the electronic spectra, witnessed upon introduction of these metal bridges, are consistent with enhanced electron delocalization in the unsaturated backbone. Control studies suggest that this electronic behavior is attributable exclusively (in the case of Ag(I)) or partially (in the case of Pd(II)) to conformational restrictions of the conjugated backbones.

Two conjugated systems that can be constrained to planarity via metal coordination have been generated and their metal complexes studied. The potential for these architectures to be incorporated into metal-sensing arylene ethynylene/vinylene oligomers and polymers was probed by verifying that these ligands (1) bind strongly to Ag(I) and Pd(II) cations, and (2) that this event leads to complexes that are planar. Single crystal structures confirm that introduction of Ag(I) or Pd(II) cations enforces planarity in the newly formed macrocycles. Likewise, (1)H-NMR titration studies reveal stoichiometric binding of Pd(II) and strong binding of Ag(I) (K(a (Ligand 1)) = 1.3 × 10(2) M(-1); K(a (Ligand 2)) = 5.4 × 10(2) M(-1)) for each conjugated ligand.

The sodium hydrogen exchanger (NHE1) plays a role in intracellular pH homeostasis and acts as scaffolding anchor for a diverse set of proteins. The extended carboxyl terminus is phosphorylated by seven known protein kinases. Phosphorylation site of NHE1 by RhoA Kinase (Rock) was recently defined and found critical for a number of cellular functions. However, the impact of Rock phosphorylation on NHE1‐related signaling for a range of agonists has not been determined. Here we examine three different signaling pathways and the role Rock phosphorylation of NHE1. Using stably expressing tagged NHE1 we identify proteins co‐immunoprecipitating with NHE1 in control and agonist stimulated cells. Cellular function of adhesion and proliferation is also presented. Finally the influence of Rock phosphorylation of NHE1 on cellular migration was determined for three signaling pathways using an impedance‐based assay. This work was supported with funds from NSF MCB‐0817784