Copper(I) binds to 2,7-diimino-1,8-naphthyridine in solution to form a mixt
ure of equilibrating mono- and polynuclear complexes, as identified by elec
trospray MS and monitored by UV-visible spectrophotometric titrations, incl
uding a binuclear metallo-helicate for which X-ray data are available but w
hose formation does not require cooperative associations.