p-Nitroanilines have elicited broad interest and application in the fields of materials and analytical sciences on account of their solvatochromism1-7 and nonlinearoptical (NLO) properties.8-13 The relevant structural feature of these chemicals is their “push-pull” π-conjugated electron arrangement. A variety of substituted p-nitroanilines act as solvent-sensitive (solvatochromic) indicators. The solvent-dependent shifts of their UV/vis spectral bands form the basis of several solvent polarity scales.1-3 Newer, more hydrophobic forms of these indicators are presently being developed as probes of the polarity of solute binding environments and of permeability in micelles, lipid bilayers, and biological membranes.7,14-15 p-Nitroanilines also exhibit relatively large first-order hyperpolarizabilities (â),8,10,13 the molecular phenomenon associated with second-harmonic generation (SHG), which refers to the doubling of the frequency of transmitted light. The latter material property is a potentially very useful NLO effect and is highly sought as it can be exploited to create memory storage devices, switches, and radiation-protective coatings.16 In this work, we focus on some new long-chain N,Ndialkyl-p-nitroanilines: N,N-dipentyl-, N,N-dihexyl-, N,Ndioctyl-, N,N-didecyl-, and N,N-didodecyl-p-nitroanilines (Figure 1). Compounds 1c-g (Figure 1) constitute new hydrophobic forms of the solvatochromic π* indicators of solvent dipolarity/polarizability.1,4 These new dyes also may be useful in furthering our understanding of the potential utility of alkyl chain length as a strategy for designing crystal lattices of p-nitroanilines with high SHG activity. The n-alkyl-p-nitroanilines recently have been investigated in this respect.13 Some practical approaches for the synthesis of 1a-g as well as a discussion of crystallographic structures of the long-chain (N,Ndidecyl) vs short-chain (N,N-dipropyl) di-n-alkyl dyes are addressed briefly here. A preliminary look at the solvatochromic properties of 1f and 1g in comparison to the shorter chain homologues also is given.