Monomer, dimer or cyclic helicate? Coordination diversity with hard-soft P,N-donor ligands.

We report the synthesis of copper(I) complexes of three ligands which contain a potential P,N,N,P-metal binding site. Elemental analysis confirms that the bulk products possess a composition of [CuL][PF6] where L = 1, 2 or 3. Electrospray mass spectrometry (ESI MS) provides evidence for speciation in MeCN or MeOH solutions and the formation of both [CuL]+ and [Cu2L2]2+; addition of NaCl to the ESI MS samples aids the observation of dinuclear species as [Cu2L2Cl]+ ions.

The d10 route to dye-sensitized solar cells: step-wise assembly of zinc(II) photosensitizers on TiO2 surfaces.

Dye-sensitized solar cells have been assembled using a sequential approach: a TiO(2) surface was functionalized with an anchoring ligand, followed by metallation with Zn(OAc)(2) or ZnCl(2), and subsequent capping with a chromophore functionalized 2,2':6',2''-terpyridine; the DSCs exhibit surprisingly good efficiencies confirming the effectiveness of the new strategy for zinc-based DSC fabrication.

2,2':6',2''-terpyridine substituted in the 4'-position by the solubilizing and sterically demanding tert-butyl group: a surprisingly new ligand.

We describe the synthesis and characterization of 4'-tert-butyl-2,2':6',2''-terpyridine (4'-(t)Butpy, 1), a convergent tpy ligand that exhibits both a sterically demanding and solubilizing 4'-substituent. In the solid state, molecules of 1 pack with alternating tpy and tert-butyl domains, and the bulky alkyl substituents prevent the molecules from engaging in the face-to-face π-interactions which are typical of simple tpy ligands. Instead, the predominant packing forces involve CH···N hydrogen bonds and weak CH···π contacts.

Oligoazobenzenes--switching in a new dimension.

A new synthesis of cyclotrisazobenzene with different substituents was developed with yields of up to 30%. Solid-state structures of cyclotrisazobenzene as well as the tert-butyl derivative were obtained. Also, the photochromic properties and the complexation behaviour with alkali metal ions of this class of molecules were investigated.