Rate studies have shown that the activation of halogenobenzenes towards nucleophilic attack by methoxide ion in methanol increases through theseriesof x-attached residues : (OC),Cr < (OC),Mo < (q5-CsH5)Fe+ < (OC),Mn+.For a given (x-arene) metal system, the reactivity of halogenoarene ligands towards methoxide decreases through the series: fluorobenzene > chlorobenzene chlorotoluene. Rates of reaction with methoxide are retarded in the presence of NaCIO, or LiCI, but accelerated when the methanol solvent is diluted with tetrahydrofuran or 1'4dioxan. Fluorobenchrotrene (OC),Cr(qs-PhCI) is slightly more reactive towards ethoxide in ethanol than towards methoxide in methancl. Evidence has been obtained that the cationic (ha1ogenoarene)metal complexes readily form ion-pairs with methoxide, resulting in a reduction in their reactivity towards nucleophilic attack. Methoxide adds to [ (x-methoxyarene) Mn(CO),] + complexes to give (q5-cyclohexadienyl) products which are reconverted into the cations by acid treatment.ALTHOUGH unactivated halogenoarenes are inert to stitution to an extent similar in magnitude to the effect nucleophilic substitution under normal conditions,l their of a 4-nitro-substituent, although different mechanisms x-complexes with transition metal-ligand residues readily of electron withdrawal operate for the two systems,8 undergo SNAr reactions with anionic and neutral and that x-complexation with an ( q5-C,H,)Fe+ residue nucleopliiles.2 Such activation was first reported by exerts an even more marked effect.9 Since (q6-arene)metal complexes are available in a wide diversity of structural types,2J0 and in view of the current interest in the mechanistic details of SNAr reactions,ll we have measured the rates of reactions of a series of neutral and cationic (q6-ha1ogenoarene)metal complexes (1)-(4) with a range of anionic and neutral nucleophiles.In this paper,I2 we report the results of reactions with alkoxide ions.

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In societies emerging from conflict, education plays an important part in instituting peace and reconciliation, and school leaders are key to this. This paper explores the role of school leaders in Northern Ireland, a society emerging from conflict. Despite the peace agreement of 1998, Northern Ireland's communities are still deeply divided, and this is reflected in education. The school leaders who were interviewed as part of this research work within school partnerships as part of 'shared education' projects which involve schools working together and with twin aims of improving both educational and reconciliation outcomes for young people. The challenges that school leaders face when working in partnership in post-conflict societies have not been given the attention they deserve in the literature, so this work is significant in that it brings together a focus on school, drawing on theories of turbulence to examine how principals can best be empowered to be agents of change, in turn empowering pupils. While the focus is on Northern Ireland, the outcomes from this study will be of wider interest and significance for school leaders facing similar challenges in other divided situations.