High-precision 14 N NMR shieldings are reported for all five aromatic compounds ( azines ) (4‐6) , as well as for fused available oxazoles and oxadiazoles in a variety of solvents. Both five- and six-membered ring systems ( indolizines ) (7 ). solvent polarity and hydrogen-bond effects on the nitrogen nuclear These solvent effects on the nitrogen shielding are significant shieldings of the solutes are significant and comparable in magni- and variable in magnitude. tude; both give rise to shielding increases. The increasing solvent There is a clear distinction in solvent effects on nitrogen polarity favors delocalization of electrons from oxygen atoms into shielding between the pyrrole and the pyridine types of nitrothe heteroaromatic rings with a concomitant electron charge accu- gen atom (1‐7) . For the pyridine type, the effect of solvent mulation on the nitrogen atoms concerned. This trend is parallel polarity / polarizability is to increase the nitrogen shielding to those found for analogous diazole and triazole heteroaromatic by up to 10 ppm. These nitrogen atoms are also hydrogensystems. Solvent-to-solute hydrogen bonding causes an increase in bond acceptors, and their interactions with hydrogen-bond nitrogen shielding when the nitrogen atoms in question are involved in the hydrogen bonding as acceptor sites. This reflects not donor solvents can also yield a shielding increase by up to only local effects of hydrogen bonding to a particular nitrogen 25 ppm. Such effects are valuable in disclosing the relative atom but also those arising from competition between other ac- basicities of nonequivalent nitrogen atoms in both five- and ceptor sites in a given molecule; these include oxygen and other six-membered rings. nitrogen atoms. TNDO/2-calculated nitrogen shieldings, with re- Pyrrole-type nitrogen atoms experience much smaller solspect to neat nitromethane, give a very good linear correlation vent effects on their nuclear shieldings. The most significant with experimental results when all of the nitrogen atoms in the contribution is produced by solvent polarity which is oppomolecules studied are taken into account. The present study of site to that found for pyridine-type nitrogen atoms. Hydronitrogen shieldings provides a valuable insight into solvent polarity gen-bonding effects become important for pyrrole-type nieffects on electric charge distribution in nitrogenous heteroaro- trogen atoms only when they are contained within an NH matic systems, as well as into possible competition between various moiety where the hydrogen atom can be involved in hydrohydrogen-bond acceptor centers with respect to hydrogen-bond