Iron and copper are metals which play an important role in the living world. From a brief consideration of their chemistry and biochemistry we conclude that the early chemistry of life used water soluble ferrous iron while copper was in the water-insoluble Cu(I) state as highly insoluble sulphides. The advent of oxygen was a catastrophic event for most living organisms, and can be considered to be the first general irreversible pollution of the earth. In contrast to the oxidation of iron and its loss of bioavailability as insoluble Fe(III), the oxidation of insoluble Cu(I) led to soluble Cu(II). A new iron biochemistry became possible after the advent of oxygen, with the development of chelators of Fe(III), which rendered iron once again accessible, and with the control of the potential toxicity of iron by its storage in a water soluble, non-toxic, bio-available storage protein (ferritin). Biology also discovered that whereas enzymes involved in anaerobic metabolism were designed to operate in the lower portion of the redox spectrum, the arrival of dioxygen created the need for a new redox active metal which could attain higher redox potentials. Copper, now bioavailable, was ideally suited to exploit the oxidizing power of dioxygen. The arrival of copper also coincided with the development of multicellular organisms which had extracellular cross-linked matrices capable of resisting attack by oxygen free radicals. After the initial 'iron age' subsequent evolution moved, not towards a 'copper age', but rather to an 'iron-copper' age. In the second part of the review, this symbiosis of iron and copper is examined in yeast. We then briefly consider iron and copper metabolism in mammals, before looking at iron-copper interactions in mammals, particularly man, and conclude with the reflection that, as in Greek and Roman mythology, a better understanding of the potentially positive interactions between Mars (iron) and Venus (copper) can only be to the advantage of our species.

A novel type of cryptation involving only the r-binding sites of the cavity [2.2.2]paracyclophane is evidenced through solubility and 'H NMR studies. The stability constant, in methanol, of the 1:l complex of [2.2.2]paracyclophane with silver triflate is approximately 100-fold higher than those of the usual r-charge-transfer complexes of arenes with silver cation. The well-defined, sharp-melting, crystalline, 1 : 1 complex has been isolated and characterized.

Keywords: Zn II Fe III complex / Fe II Fe III complex / Purple acid phosphatases / Phosphate ester hydrolysisThe heterodinuclear Zn II Fe III complex 1 and the isostructural Fe II Fe III complex 2 with the dinucleating ligand from 2,6-bis[{bis(2-pyridylmethyl)amino}methyl]-4-methoxyphenol (HBPMOP, 3) were prepared and characterized by X-ray crystallography. Solution studies (UV/Vis spectroscopy; electrochemistry) are described. A pH-induced change in the coordination spheres of the metal centers is seen. These complexes serve as models for the mixed-valence oxidation state in purple acid phosphatases. The cleavage acceleration of the activated phosphodiester 2-hydroxypropyl p-nitrophenyl