NOVELTY - Complex comprises: a metal colloid comprising many iridium atoms; and a calixarene-related compound comprising a linker. The linker comprises a coordinating atom coordinated to one of the iridium atoms.    USE - The complex is useful: to synthesize a calixarene-bound metal colloid; in catalytic processes of reducing or oxidizing organic molecule (all claimed); to tune the electronic environment, steric access and patterning; for controlling aspects of the reactivity of iridium-containing metal colloids by coordination with calixarene-related moieties; to catalyze metal-mediated processes comprising olefin rearrangements, hydroformylation of olefins, cycloaddition of terminal alkanes, oxidation processes, hydrogenation processes and acid-catalyzed reactions; as hydroprocessing catalyst; in propane hydrogenolysis, carbon monoxide hydrogenation, toluene hydrogenation, methanation, intramolecular hydroamination, asymmetric isomerization of primary allylic alcohols, allylic amination, hydroamination, hydrothiolation, C-H bond arylation of heteroarenes using iodoarenes, (2+2+2) cycloadditions, carbonylation, methane hydroxylation, naphthenic ring opening, hydrogenation reactions comprising alpha , beta -unsaturated aldehydes, cyclization reactions comprising terpenoids (e.g. transformation of citronellal to menthol), ring opening reactions comprising cycloalkyls (e.g. conversion of methylcyclohexane to dimethylpentane or naphthenic ring opening), steam catalytic reforming of nitrogen monoxide and hydroconversion reactions, cycloalkyls (e.g. cyclohexene).    ADVANTAGE - The complex: provides tunable and highly robust metal colloids; and maintains protection of the metal moiety against aggregation/decomposition while also simultaneously providing for accessibility to molecules that can bind and/or react at the surface of the metal moiety.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a metal colloid formed by a process comprising performing a reaction on the complex, where the reaction is pyrolysis, thermal decomposition and/or oxidative decomposition;    (2) synthesizing a calixarene-bound metal colloid, comprising contacting the calixarene-related compound with a colloidal metal bromide under conditions to cause bromide anion displacement from the colloidal metal bromide;    (3) a catalytic process-1 comprising reducing an organic molecule by contacting the organic molecule with the complex or the metal colloid and a reductant; and    (4) a catalytic process-2 comprising oxidizing an organic molecule by contacting the organic molecule with the complex or the metal colloid and an oxidant.