Cyclic carbonate and δ-valerolactone substrates functionalized with ferrocene were synthesized via alkyne-azide "click" cycloaddition. The cyclic carbonates were polymerized using 1,8-diazabicycloundec-7-ene, 1-(3,5-bis(trifluoromethyl)phenyl)-3-cyclohexylthiourea, and benzyl alcohol. The resulting polymers were characterized by GPC, NMR spectroscopy, and cyclic voltammetry studies. It was found that polycarbonate molecular weights fall in the range of 4.1-5.2 × 103 g mol-1 with polydispersities as low as 1.26. Electrochemistry studies allowed us to identify the monomer/polymer pair with the most desirable redox potential for biological studies.

Most binary materials formed by early group 13 and 15 elements are semiconductors identical in their structures and properties. We show that in the ultra-small cluster regime these materials are markedly different. Among X(X = B, Al, Ga; Y = P, As), lighter clusters are planar, and heavier clusters are compact and three-dimensional. The difference is owed to the interplay between covalency and delocalized non-directional bonding in these systems. If the sp-hybridization in the constituent elements is energetically affordable and leads to strong directional overlap, the bonding is covalent and the cluster is flat. Otherwise, the cluster is three-dimensional. © 2013 Elsevier B.V. All rights reserved.