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The complexes [Pd(phen)(aa)]Cl·3H2O, where phen is 1,10-phenanthroline and as is the anion of glycine (gly), DL-alanine (ala), DL-serine (ser) or DL-asparagine (asn), were synthesized and characterized by spectroscopies. The NMR signals were assigned completely on the basis of the double irradiation, 1H-1 H COSY and 1H-13C COSY techniques. In the 1H NMR spectra of phen in the complexes, the signals of 2-H and 9-H show upfield shifts 0.8–1 ppm, while the signals of 4-H and 3-H show downfield shifts or almost no shift, as compared to the free phen ligand, and the signal of 4-H appears in the lowest field. The signals of ring B which is trans to the carboxyl group show significant upfield shirts as compared to those of ring A. The probable structures were described on the basis of a metal-non-bonded hydrogen interaction, trans effect and ligand-ligand interaction. There may exist three conformation isomers in the [Pd(phen)(asn)]Cl·3H2O complex at room temperature. The preferred conformation isomer is about 75% in terms of the relative peak areas in the α-CH part of the spectra.

Starting from 1,10-phenanthroline, a series of novel ligands(L), imidazo[f]1,10-phenanthroline (IP), 2-phenylimidazo[f]1,10-phenanthroline (PIP) and the derivatives, and their complexes [Ru(bpy) 2 L] 2+ have been synthesized and characterized. The effects of different electron donor and acceptor groups on the 1 H NMR, electronic absorption and emission spectra were studied. Time-resolved luminescence studies revealed that the addition of calf thymus DNA into the complex solution results in increases for both the emissive intensities and excited state lifetimes, and indicates that the electron group on L has no significant effect on the intercalation binding mode between DNA and the complexes.

Two ruthenium(II) complexes with polypyridyl, Ru(bipy)2(phen)](ClO4)2·H2O (1) and [Ru(bipy)2(Me-phen)](ClO4)2 (2), (phen = 1,10-phenanthroline, bipy = 2,2′-bipyridine, Me-phen = 5-methyl-1,10-phenanthroline), were synthesized and characterized by IR, MS and NMR spectra. Their structures were determined by single crystal X-ray diffraction techniques. The strong steric interaction between the polypyridyl ligands was relieved neither by the elongation of the RuN bonds nor increase of the NRuN bite angles. The coordination sphere was distorted to relieve the ligand interaction by forming specific angles (δ) between the polypyridyl ligand planes and coordination planes (NRuN), and forming larger twisted angles between the two pyridine rings for each bipy. The bond distances of RuN(bipy) and RuN(phen) were virtually identical with experimental error, as expected of π back-bonding interactions which statistically involve each of the ligands present in the coordination sphere.

Two cobalt(III) complexes with phenanthroline, [Co(phen)2(gly)]Cl2 · 4H2O (1) and [Co(phen)2(H2O)2](NO3)3 · 2H2O (2), (phen = phenanthroline and gly = glycine), were synthesized and characterized by IR and NMR spectra. Their structures were determined by single crystal X-ray diffraction techniques. The coordinated cations all contain a six-coordinated cobalt atom chelated by two phen ligands and one gly anion or two aqua ligands in cis arrangement. The CoN bond distances in the cations lie in the range 1.934–1.952 A, the bond distances of CoO = 1.919 A (H2O) are significantly longer than that of CoO = 1.884 A (COO−). The complex 2 contains a crystallographic two-fold axis.

The complex was prepared by reaction of cis-[Co(phen)2-Cl2] Cl·3H2O (phen = phenanthroline) with L-proline at pH 9, isolated by chromatography using an SP-Sephadex C-25 H+ form column, and characterized by elemental analysis, spectroscopy and thermogravimetry. The X-ray crystal structure has also been determined. There are 1.5 independent complex cations, 1.5 ClOinf4sup−anions and two H2O molecules in each asymmetric unit, and two complex cations of similar structure in the crystal. There is a crystallographic C2 symmetry in the first of these. In the octahedral coordination sphere of the metal the oxygen and nitrogen chelating prolinato ligands are arranged in the trans-N,N form.

A series of new complexes [RuL2(pdphen)]2+, where pdphen is the planar ligand pyridino[3,2-f] [1,7]phenanthroline and L = 2,2′-bipyridine, phenanthroline, 2,9-dimethylphenanthroline or 5-nitrophenanthroline, were prepared and characterized. The binding of [RuL2-(pdphen)] 2+ to calf thymus DNA was investigated using absorption, fluorescence and circular dichroism (c.d.) spectroscopies. All of the complexes show absorption hypochromicity associated with binding to calf thymus DNA. [Ru(bipy)2pdphen]2+ and [Ru(phen)2pdphen]2+ also show fluorescence intensities and excited state life-time increases. The c.d. spectra of dialyzates from solutions of racemic complexes versus calf thymus DNA indicate enantioselectivity associated with binding to DNA.