Acetone

Reagents (Mo(CO)₆, 1H-1,2,3-triazole (97%, Manchester Organics, Runcorn, UK), 1H-1,2,4-triazole (98%), 5–6 M tert-butyl hydroperoxide in decane, anhydrous dichloromethane, toluene (99.9%), acetone (99.5%), diethyl ether (99.8%) and pentane (≥95%, Carlo Erba, Milan, Italy) were purchased from Sigma-Aldrich (St. Louis, MO, USA) unless otherwise indicated. For the catalytic experiments, cis-cyclooctene (95%), acetonitrile (≥99.9%), anhydrous α,α,α-trifluorotoluene (99%), pentane (≥99.5%) and 30% aq. H₂O₂ were acquired from Sigma-Aldrich and used as received. The hybrid metal oxide-triazole material [MoO₃(1,2,4-trz)_0.5] (4) was prepared by the hydrothermal reaction of MoO₃, 1,2,4-trz and water at 180 °C for 1 h [13 (link)]. The phase purity of the microcrystalline product was verified by a comparison of its powder X-ray diffraction (PXRD) pattern with a simulated pattern calculated using the crystal structure data published for 4 (Figure S4 in the Supporting Information) [13 (link)]. The trinuclear complex (1,2,4-Htrz)₂[Mo₃O₆(O₂)₄(1,2,4-trz)₂]⋅H₂O (6) was prepared as described previously by the addition of 1,2,4-trz to the solution obtained upon reaction of MoO₃ with a large excess of H₂O₂ [26 (link)].

Acetone (CAS No. 67-64-1), methanol (CAS No. 67-56-1), ethanol (CAS 64-17-5), ethyl acetate (CAS No. 141-78-6), ethyl lactate (CAS No. 687-47-8) and n-hexane (CAS No. 110-54-3) were obtained from Carlo Erba (Milano, Italy). Butylated hydroxytoluene (BHT, CAS No. 128-37-0), potassium persulfate (CAS No. 7727-21-1), Trolox [6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid] (CAS No. 53188-07-1) and ABTS [2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt] (CAS No. 30931-67-0) were provided by Sigma–Aldrich (St. Louis, Mo, USA). All chemicals were of analytical grade and used as received.
Fresh ripe tomatoes of the variety Piccadilly were purchased from a local market and stored in the dark at 4 °C. Before each set of experiments, a few tomato fruits were immersed in boiling water for 1–2 min, cooled in tap water and hand peeled. Tomato peels were left to dry in air for about 2 h and then characterized for total lycopene and moisture content.
Natural lycopene standard (10% by weight) was obtained from LycoRed Natural Products Industries Ltd. (Beer-Sheva, Israel).