The low-temperature interaction of sublimed layers of manganese(tl) meso-tetraphenytporphyrinate (MnTPP) with O 2, which has previously been observed only in solutions and in an inert gas matrix, was found by electron absorption and IR spectroscopy. The coordination of 02 with sublimed MnTPP layers is only partially reversible. Bands that can serve as IR-spectral markers characteristic of the high-spin Mn II ion in MnTPP and its axial complexes were observed.

Interactions of meso-tetra-(4-N-oxyethylpyridyl) porphyrin (TOEPyP(4)), its 3-N analog (TOEPyP(3)) and their Co, Cu, Ni, Zn metallocomplexes with duplex DNA have been investigated by uv/visible absorbance and circular dichrosim spectroscopies. Results reveal the interactions of these complexes with duplex DNA are of two types. (1) External binding of duplex DNA by metalloporphyrins containing Zn and Co, and (2) Binding of duplex DNA both externally and internally (by intercalation) by porphyrins not containing metals, and metalloporphyrins containing Cu and Ni. Results indicate that (4N-oxyethylpyridyl) porphyrins intercalate more preferably in the structure of duplex DNA and have weaker external binding than 3N-porphyrins.

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The interaction of CO, NO and O 2 gases with thin layers of meso-mono-4-pyridyltri-phenylporphyrinatoiron(II) (FeMPyTPP) obtained by sublimation onto low-temperature (T = 77 K) substrates has been investigated by means of IR and UV-visible spectroscopy. In contrast to the closely-related meso-tetraphenylporphyrinatoiron(II) (FeTPP), the formation of two types of axial complexes has been observed. In one of these the 5th coordination site is occupied by the pyridyl group of an adjacent molecule indicating the self-assembly of Fe(MPyTPP) in layers with formation of coordinatively linked oligomers. The degree of oligomerisation depends on the nature of the interacting gas. Due to the specificity of the supramolecular structure, the layers are fairly stable in ambient conditions and conserve their microporosity to bind reversibly with the aforementioned ligands.

The interaction of O 2 (18 O 2 ) with [meso-triphenyl(4-pyridyl)-porphyrinato]cobalt(II) [Co(MPyTPP)] has been investigated by means of IR spectroscopy under matrix-isolation conditions and by the action of dioxygen on thin sublimed layers. These studies have led to the characterisation of two dioxygen adducts: (1) a very unstable dioxygen adduct similar to that observed earlier for the closely related [mesotetraphenylporphyrinato]cobalt(II) Co(TPP), and (2) a new type of coordinated O 2 ( 18 O 2 ) complex which is formed after warming Co(MPyTPP) either in pure oxygen matrices, or as sublimed layers in the presence of oxygen. The ν(O 2 ) vibration in this second species is more than 100 cm −1 lower than