Fused H-shaped tetrathiafulvalene-oligothiophenes as charge transport materials for OFETs and OPVs

A series of hybrid tetrathiafulvalene-oligothiophene compounds has been synthesised, where the tetrathiafulvalene unit is fused at each side to an end-capped oligothiophene chain of varying length (terthiophene, quinquithiophene and septithiophene). Each hybrid structure (1-3) has been studied by cyclic voltammetry and triple EPR-UV-Vis-NIR spectroelectrochemistry in the case of the quinquithiophene compound (2). Comparison is made with the corresponding half-units, which lack the fulvalene core and contain just one oligothiophene chain. The highest hole mobility of quinquithiophene-TTF 2 was obtained from field effect transistors (8.61 × 10-3 cm 2 V-1 s-1); its surface morphology was characterised by tapping mode atomic force microscopy and a power conversion of 2.5% was achieved from a bulk heterojunction organic solar cell device using PC71BM as the acceptor. This journal is © the Partner Organisations 2014

One-Carbon Extrusion from a Tetraazafulvalene. Isolation of Aldehydes and a Study of Their Origin

Reaction of imidazolylidene-derived enetetramine <b>2</b> with aliphatic iodides and bromides (and with aryl iodides bearing alkene-containing side-chains in the ortho-position) leads to formation of aliphatic aldehydes through an unprecedented extrusion of a one-carbon unit from the enetetramine. An intermediate 2-alkylimidazoline <b>24</b> is proposed, where the alkyl group derives from the substrate; this imidazoline undergoes further reaction in situ to afford the observed aldehydes on acidic workup. Modified substrates were designed and prepared to probe the chemistry of the alkylimidazoline adducts and provided extensive information on the chemistry of the adducts

Reductions of Challenging Organic Substrates by a Nickel Complex of a Noninnocent Crown Carbene Ligand

The first crown-tetracarbene complex of Ni(II) has been prepared, and its crystal structure determined. The complex can be reduced by Na/Hg, with an uptake of two electrons. The reduced complex reductively cleaves arenesulfonamides, including those derived from secondary aliphatic amines, and effects Birch reduction of anthracenes as well as reductive cleavage of stilbene oxides. Computational studies show that the orbital that receives electrons upon reduction of the complex <b>2</b> is predominantly based on the crown carbene ligand and also that the HOMO of the parent complex <b>2</b> is based on the ligand

Reductions of Challenging Organic Substrates by a Nickel Complex of a Noninnocent Crown Carbene Ligand

The first crown-tetracarbene complex of Ni(II) has been prepared, and its crystal structure determined. The complex can be reduced by Na/Hg, with an uptake of two electrons. The reduced complex reductively cleaves arenesulfonamides, including those derived from secondary aliphatic amines, and effects Birch reduction of anthracenes as well as reductive cleavage of stilbene oxides. Computational studies show that the orbital that receives electrons upon reduction of the complex <b>2</b> is predominantly based on the crown carbene ligand and also that the HOMO of the parent complex <b>2</b> is based on the ligand