Using alcohols as alkylation reagents for 4-cyanopyridinium and N,N '-dialkyl-4,4 '-bipyridinium and their one-dimensional iodoplumbates

Solvothermal reactions of PbI2 with 4-cyanopyridine (4-cypy) or 4,4'-bipyridine (4,4'-bipy) and alcohols (ethanol, propanol, iso-propanol, benzyl alcohol, alpha,alpha'-dihydroxy-p-xylene) in the presence of PbI2, I-2 and a trace amount of water in acetonitrile gave rise to a family of 1D iodoplumbate complexes of 4-cyanopyridinium and N,N'-dialkyl-4,4'-bipyridinium including {[EC](4)[(Pb2I6)(2)]center dot 2MeCN}(n) (EC+ = N-ethyl-4-cyanopyridium) (1), {[PC][PbI3]}(n) (PC+ = N-propyl-4-cyanopyridium) (2), {[iPC](3)[(PbI3)(Pb2I6)]}(n) (iPC(+) = N-isopropyl-4-cyanopyridium) (3), {[BzC][PbI3]}(n) (BzC(+) = N-benzyl-4-cyanopyridium) (4), {[Cxy](2)[(Pb2I6)(2)]}(n) (Cxy(2+) = 1,4-bis(4-cyanopyridium)-xylene) (5), {[EV](1.5)[Pb3I9]}(n) (EV2+ = N,N'-diethyl-4,4'-bipyridinium) (6), {[PV](1.5)[Pb3I9]}(n) (PV2+ = N,N'-dipropyl-4,4'-bipyridinium) (7), and {[iPV](2)[Pb4I12]}(n) (iPV(2+) = N,N'-diisopropyl-4,4'-bipyridinium) (8). The resulting 4-cyanopyridinium and viologen cations were generated in situ via the cleavage of C-O bond of alcohols followed by alkylation of 4-cypy or 4,4'-bipy. X-Ray analysis revealed that compounds 1-8 contain one-dimensional anionic [PbI3](n)(n-) (1-5, 8) and [Pb3I9](n)(3n-) (6 and 7) chains that are enclosed into the different cationic channels formed from the 4-cyanopyridinium and N,N'-dialkyl-4,4'-bipyridinium. In addition, the optoelectronic and dielectric properties of 1-8 were also investigated.