TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: Hal is most preferably bromo; all A are the same, especially O or S; all ligands have the same basic structure and Q = N, para to the co-ordinating nitrogen but CH at other positions; M is particularly Al or Ga.Preparation: Halogenation is with an organic N-bromo compound (X), optionally in presence of a Lewis acid (Y); with bromine or a Br-halo compound in presence of organic base; or with an organic bromine complex, optionally in presence of (Y). The brominating reagent is used in a stoichiometric amount.    TECHNOLOGY FOCUS - POLYMERS - Preferred Materials: Polymers that may include (I) as monomers are specifically polyfluorene; polyspirobifluorene; polydihydrophenanthrene; poly-p-phenylene; polycarbazole; and polythiophene. Full Definitions:    M = Al, Ba, Be, B, Cd, Ca, Cs, Ga, Ge, Au, In, Ir, K, Li, Mg, Mo, Os, Pd, Pt, Hg, Re, Rh, Rb, Sc, Ag, Sr, Te, Ti, Y, Zn, Zr, lanthanides and actinides, but M is not Ga, Au, In, Ir, Mo, Os, Pd, Pt, Hg, Rh or Zn where all A = sulfur;    each L' = 1-35C, linear, branched or cyclic alkyl or alkoxy, 1-40C (hetero)aryl or (hetero)aryloxy, cyano, carboxy, iso(thio)cyano, amido, amino, silanyl, halo, hydroxy, thiol, thiolate, thioether or oxo, or two or more L' may together combine to form a ring, or each L' is a group (Ia);    each X = fluoro, chloro, bromo, iodo, O, S, N(R)2, water, OR, SR, cyano or carbon monoxide;    each R = hydrogen, fluoro, chloro, bromo, iodo, cyano, formyl, carboxy, COOR1, CON3, COCl, nitro, N(R1)2, B(R1)2, Si(R1)3 or 1-35C, linear, branched or cyclic alkyl or alkoxy (where one or more non-adjacent C may be replaced by -CR1=CR1-, ethyndiyl, NR1, O, S, COO or OCOO, and one or more hydrogen may be replaced by fluoro), 5-40C aryl or aryloxy (with one or more C optionally replaced by O, S or N, also optionally substituted by one or more R1), provided that R must be hydrogen at the position ortho to the coo-ordinating atom, if Q is CR for all ligands at this position, and two or more R may together complete an aliphatic or aromatic, mono- or poly-cyclic system;    each R1 = hydrogen, 1-22C linear, branched or cyclic alkyl (optionally with one or more non-adjacent C replaced by O, S, COO or OCOO, and one or more hydrogen may be replaced by fluoro), 5-40C aryl (optionally with one or more C replaced by O, S or N, itself optionally substituted by one or more non-aromatic residues R1) and two or more R1 may together form an aliphatic or aromatic, mono- or poly-cyclic system;    c = 1-5;    n+a+c = 1-6    EXAMPLE - A stirred solution of tris(8-hydroxyquinolinato)aluminum(III) (30 g) in dimethylformamide (1 l) was treated (excluding light) with N-bromosuccinimide (35.6 g) and stirring continued for 20 hours at room temperature. The suspension formed was filtered; the organic phase concentrated to 150 ml and treated with ethanol (1 l). solids were filtered off, washed 3 times with ethanol (100 ml) and dried at 60degreesC/10-4 mbar to give 44.7 g (99%) of equatorial tris(5-bromo-8-hydroxyquinolinato)aluminum(III), with purity over 99%.