achieved, differ only in the anion, their thermal spincrossover behavior differs considerably; on the other hand, the LIESST(L + H) behavior is similar in the two cases. Experimental ProcedureThe ligdnd mtz was prepared as described in the literature [16]. In order to synthesize 1, iron powder was first dissolved in aqueous 2 M trifluoromethanesulfonic acid (Aldrich). The excess iron powder was then filtered off and the solution was gently concentrated under nitrogen until [Fe(H,O),](CF,SO,), began to crystallize. The product was collected by filtration and washed with a small amount of cold water and ether. Complex 1 was obtained from a concentrated aqueoussolutionof [Fe(H,O),](CF,SO,), and mtzin amolar ratio of 1 :6 under nitrogen; the solution was further concentrated by applying a stream of oxygen-free nitrogen until 1 began to crystallize. After filtration and washing, 1 was recrystallized from nitromethane. The values of the elemental analyses are in good agreement with the theoretical values. The magnetic susceptibility 1 was measured with a Foner magnetometer in the range 20 I T 5 270 K (He-flow cryostat) in a magnetic field of 1 T. The diamagnetic correction for l was determined by 1 measurement at room temperature on an analogously prepared zinc complex (% = -648 x cm'mol-'). The value of the magnetic moment was calculated from the equation pCrr = 2.828 (rm'T)"2 (1, = corrected molar susceptibility). 57Fe Mossbauer spectra were recorded with a conventional spectrometer. The "Co/Rh source was kept at room temperature, while the absorber (enclosed in a Plexiglass container, 3 cm2 area, with ca. 7 mgcm-, Fe) was mounted in a flow cryostat (CF 506, Oxford Instruments). The cryostat was equipped with windows of transparent Mylar film. The temperature at the absorber was measured with a carboniglass resistor mounted directly on the sample holder. The Mossbauer signals were fitted to Lorentzian curves.

Interleukin (IL)-1b is known to play a role in the formation of brain edema after various types of injury. Aquaporin (AQP)4 is also reported to be involved in the progression of brain edema. We tested the hypothesis that AQP4 is induced in response to IL-1b. We found that expression of AQP4 mRNA and protein was significantly up-regulated by IL-1b in cultured rat astrocytes, and that intracerebroventricular administration of IL-1b increased the expression of AQP4 protein in rat brain. The effects of IL-1b on induction of AQP4 were concentration and time dependent. The effects of IL-1b on AQP4 were mediated through IL-1b receptors because they were abolished by co-incubation with IL-1 receptor antagonist. It appeared that IL-1b increased the level of AQP4 mRNA without involvement of de novo protein synthesis because cycloheximide, a protein synthesis inhibitor, did not inhibit the effects of IL-1b. Inhibition of the nuclear factor-jB (NF-jB) pathway blocked the induction of AQP4 by IL-1b in a concentration-dependent manner. These findings show that IL-1b induces expression of AQP4 through a NF-jB pathway without involvement of de novo protein synthesis in rat astrocytes.

The porphyrins (e.g., porphine, 1) are of ubiquitous biological importance and remain among the most widely studied of all known macrocycles. Increasingly, however, attention is being devoted to the study of larger pyrrole-containing macrocycles.Such larger systems, the so-called "expanded porphyrins",1 appear attractive with regard to a variety of biomedical applications ranging from magnetic resonance imaging (MRI)1-3 and photodynamic therapy (PDT)1•* 1234•5 to anion chelation and drug delivery.1•6While there are now a number of expanded porphyrins known,1 including penta-and hexapyrrolic macrocycles such as sapphyrin,7 pentaphyrin,8 hexaphyrin,9 and rubyrin,10 none is easy to prepare.

A new approach to the chelation of anionic substrates, based on the use of large, pyrrole-containing macrocycles, the so-called "expanded porphyrins", is described. This anion binding, which is without precedent in simpler porphyrin-type systems, is manifest both in the solid state and in solution. In the present paper, it is illustrated in terms of solid state structural results obtained from single-crystal X-ray diffraction structural analyses of various anion complexes of three prototypic systems, namely the sapphyrins, anthraphyrins, and rubyrins.The porphyrins (e.g. octaethylporphyrin, 1) and related tetrapyrrolic compounds are among the most versatile of all macrocyclic systems (ref. 1). They play, for instance, a critical role in a large number of biological processes and are widely recognized as being metal-binding ligands par excellence.Nonetheless, the porphyrins and related systems fail with regards certain applications. They are not, for instance, capable of forming hydrolytically stable, non-labile 1: 1 complexes with many cations of the lanthanide or actinide series (ref. 2). Nor, do they work as anion complexing agents (ref. 3). Recently, however, we have found that certain larger pyrrole-containing macrocyclic analogues of the porphyrins, members of the so-called expanded porphyrin series (ref. 4), can serve not only to bind cations of the lanthanide (ref. 5) and actinide series (ref. 6), but also in certain instances to chelate anions (refs. 7-17). It is this latter finding, namely the discovery of anion binding (ref. 18) in simple porphyrin-like systems, that engenders the present report. In particular, the results of solid state structural studies, carried out using three prototypic series of expanded porphyrins, the sapphyrins (e.g. 2 and 3), anthraphyrins (e.g. 4), and rubyrins (e.g. S), will be detailed and relevant solution phase results presented.Our first realization that expanded porphyrins are capable of chelating anionic substrates arose out of an attempt to obtain X-ray diffraction quality of sapphyrin 2, a decaalkyl derivative of a class of compounds first reported by Woodward nearly 25 years ago (ref. 19). Here, an X-ray crystal analysis of what was thought to be the bis-HPF6 salt of 2, revealed the presence of only one PF6-counteranion per macrocycle as well as the presence of unexpected electron density in the center of the fully protonated pentaaza core (ref. 7). On the basis of l9F NMR and independent synthesis, this unexpected electron density was ascribed to a hydrogen-bound fluoride anion, indicating, as shown in Figure 1, that the diprotonated form of 2 acts as a fluoride anion receptor--at least in the solid state. 2. R = C H 3 3. R = CH2CH20H 393 4 5

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