154ꢀ
AlirezaꢀKhorshidiꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ153–158ꢀ
catalystꢀwasꢀnotꢀrecoverable.ꢀFurthermore,ꢀpreviousꢀstudiesꢀonꢀ
ruthenium‐catalyzedꢀ oxidationꢀ ofꢀ arenesꢀ yieldedꢀ eitherꢀ dicar‐
boxylicꢀacids,ꢀtetracarboxylicꢀacids,ꢀorꢀdiolsꢀ[26–28].ꢀHerein,ꢀweꢀ
reportꢀ anꢀ improvementꢀ toꢀ theꢀ limitationsꢀ ofꢀ ourꢀ previousꢀ re‐
portꢀbyꢀusingꢀrutheniumꢀnanoparticlesꢀdispersedꢀonꢀmesopo‐
rousꢀMCM‐41ꢀtoꢀcircumventꢀtheꢀdifficultyꢀinꢀcatalystꢀrecovery.ꢀ
Theꢀcatalystꢀwasꢀfoundꢀtoꢀbeꢀefficientꢀandꢀrecyclableꢀinꢀtheꢀul‐
trasound‐assistedꢀoxidationꢀofꢀaromaticꢀcompounds.ꢀ
arenesꢀ ꢀ ꢀ
Aꢀ20‐mLꢀflaskꢀwasꢀchargedꢀwithꢀCH
2
Cl
2
ꢀ(5ꢀmL),ꢀH
2
Oꢀ(5ꢀmL),ꢀ
3
CH CNꢀ(5ꢀmL),ꢀchryseneꢀ(228.3ꢀmg,ꢀ1ꢀmmol),ꢀandꢀKBrO
3
ꢀ(0.5ꢀg,ꢀ
2.99ꢀmmol).ꢀMCM‐41‐Ruꢀ(75ꢀmg)ꢀwasꢀaddedꢀintoꢀtheꢀflask,ꢀandꢀ
theꢀdarkꢀsuspensionꢀwasꢀirradiatedꢀatꢀroomꢀtemperatureꢀforꢀ1ꢀ
h.ꢀ Theꢀ catalystꢀ wasꢀ separatedꢀ fromꢀ theꢀ reactionꢀ mediumꢀ byꢀ
filtrationꢀandꢀwashedꢀwithꢀwaterꢀandꢀacetone,ꢀandꢀthenꢀdriedꢀatꢀ
1
50ꢀ°Cꢀovernight.ꢀTheꢀreactionꢀmixtureꢀwasꢀpouredꢀintoꢀ50ꢀmLꢀ
ofꢀ water,ꢀ andꢀ theꢀ organicꢀ phaseꢀ wasꢀ separated.ꢀ Theꢀ aqueousꢀ
phaseꢀ wasꢀ extractedꢀ withꢀ CH Cl ꢀ (3×10ꢀ mL).ꢀ Theꢀ CH Cl ꢀ ex‐
2.ꢀ ꢀ Experimentalꢀ ꢀ
2
2
2
2
2
.1.ꢀ ꢀ Materialsꢀ ꢀ
tractsꢀ wereꢀ combinedꢀ withꢀ theꢀ organicꢀ phase,ꢀ washedꢀ withꢀ
brineꢀ(3×10ꢀmL),ꢀandꢀdriedꢀoverꢀanhydrousꢀsodiumꢀsulfateꢀtoꢀ
yieldꢀ aꢀ darkꢀ orangeꢀ solution.ꢀ Theꢀ solutionꢀ wasꢀ concentratedꢀ
underꢀreducedꢀpressure,ꢀandꢀtheꢀmixtureꢀwasꢀpurifiedꢀbyꢀpre‐
parativeꢀthin‐layerꢀchromatographyꢀ(n‐hexane/ethylꢀacetateꢀ=ꢀ
AllꢀmaterialsꢀwereꢀpurchasedꢀfromꢀMerckꢀandꢀusedꢀwithoutꢀ
furtherꢀ purification.ꢀ Pure‐silicaꢀ MCM‐41ꢀ wasꢀ synthesizedꢀ ac‐
cordingꢀtoꢀtheꢀliteratureꢀ[29].ꢀ
10/3),ꢀprovidingꢀchrysene‐5,6‐dioneꢀasꢀtheꢀmajorꢀproductꢀandꢀ
2
.2.ꢀ ꢀ PreparationꢀofꢀMCM‐41‐Ruꢀnanoparticlesꢀ ꢀ
2‐(2‐formylphenyl)‐1‐naphthaldehydeꢀasꢀtheꢀsideꢀproduct.ꢀTheꢀ
sameꢀprocedureꢀwasꢀalsoꢀusedꢀforꢀtheꢀreactionsꢀofꢀotherꢀareneꢀ
substrates.ꢀ ꢀ
RuCl
MCM‐41ꢀ(1.0ꢀg)ꢀinꢀ10ꢀmLꢀofꢀabsoluteꢀethanolꢀunderꢀN
phereꢀinꢀaꢀtwo‐neckedꢀroundꢀbottomꢀflask.ꢀThereafter,ꢀaꢀNaBH
3 2
·3H Oꢀ (51.8ꢀ mg)ꢀ wasꢀ addedꢀ toꢀ aꢀ suspensionꢀ ofꢀ
2
ꢀatmos‐
4
ꢀ
2.5.ꢀ ꢀ Characterizationꢀdataꢀforꢀselectedꢀproductsꢀ ꢀ
solutionꢀ (0.2ꢀ mol/Lꢀ inꢀ ethanol,ꢀ excess)ꢀ wasꢀ addedꢀ drop‐wiseꢀ
underꢀvigorousꢀstirringꢀusingꢀaꢀmagneticꢀstirrerꢀforꢀaꢀperiodꢀofꢀ
Chrysene‐5,6‐dioneꢀ (4a):ꢀ Orangeꢀ crystals,ꢀ m.p.ꢀ =ꢀ 189–191ꢀ
°C;ꢀIRꢀ(KBr):ꢀυꢀ(cm )ꢀ=ꢀ660,ꢀ713,ꢀ756,ꢀ835,ꢀ957,ꢀ1040,ꢀ1086,ꢀ
−1
2ꢀh.ꢀTheꢀentireꢀreactionꢀmixtureꢀwasꢀstirredꢀovernightꢀtoꢀstabi‐
lizeꢀtheꢀRuꢀnanoparticlesꢀaccordingꢀtoꢀtheꢀMCM‐41ꢀframework.ꢀ
Theꢀobtainedꢀdark‐grayꢀproductꢀ(MCM‐41‐Ru)ꢀwasꢀfilteredꢀandꢀ
washedꢀwithꢀethanolꢀfollowedꢀbyꢀdryingꢀatꢀ150ꢀ°Cꢀovernight.ꢀ
1250,ꢀ1298,ꢀ1364,ꢀ1447,ꢀ1483,ꢀ1595,ꢀ1662,ꢀ1693,ꢀ1767,ꢀ2927,ꢀ
1
3
3066;ꢀ HꢀNMRꢀ(500ꢀMHz,ꢀCDCl ,ꢀ25ꢀ°C):ꢀδꢀ=ꢀ7.52ꢀ(t,ꢀJꢀ=ꢀ7.5ꢀHz,ꢀ
1H),ꢀ7.60ꢀ(t,ꢀJꢀ=ꢀ7.7ꢀHz,ꢀ1H),ꢀ7.74ꢀ(t,ꢀJꢀ=ꢀ8.5ꢀHz,ꢀ1H),ꢀ7.77ꢀ(t,ꢀJꢀ=ꢀ8.1ꢀ
Hz,ꢀ1H),ꢀ7.87ꢀ(d,ꢀJꢀ=ꢀ7.9ꢀHz,ꢀ1H),ꢀ8.12ꢀ(d,ꢀJꢀ=ꢀ8.6ꢀHz,ꢀ2H),ꢀ8.18ꢀ(d,ꢀJꢀ
=ꢀ7.4ꢀHz,ꢀ1H),ꢀ8.20ꢀ(d,ꢀJꢀ=ꢀ8.6ꢀHz,ꢀ1H),ꢀ9.43ꢀ(d,ꢀJꢀ=ꢀ8.8ꢀHz,ꢀ1H)ꢀ
2.3.ꢀ ꢀ Characterizationꢀofꢀcatalystꢀ ꢀ
ppm;ꢀ 13Cꢀ NMRꢀ (125ꢀ MHz,ꢀ CDCl
,ꢀ 25ꢀ °C):ꢀ δꢀ =ꢀ 121.54,ꢀ 125.64,ꢀ
3
IRꢀspectraꢀwereꢀrecordedꢀonꢀaꢀShimadzuꢀFTIR‐8400Sꢀspec‐
126.34,ꢀ127.62,ꢀ128.09,ꢀ129.09,ꢀ130.32,ꢀ130.45,ꢀ131.09,ꢀ131.28,ꢀ
132.67,ꢀ134.23,ꢀ136.49,ꢀ137.06,ꢀ137.78,ꢀ138.29,ꢀ182.45,ꢀ184.63ꢀ
1
13
trometer.ꢀ HꢀNMRꢀspectraꢀandꢀ CꢀNMRꢀspectraꢀwereꢀobtainedꢀ
onꢀaꢀBrukerꢀDRX‐500ꢀ(orꢀ125)ꢀAdvanceꢀSpectrometer.ꢀChemi‐
calꢀ shiftsꢀ wereꢀ expressedꢀ inꢀ ppmꢀ downfieldꢀ fromꢀ tetrame‐
thylsilaneꢀasꢀtheꢀinternalꢀstandard.ꢀMeltingꢀpointsꢀwereꢀmeas‐
uredꢀ onꢀ aꢀ Büchi®B‐540ꢀ meltingꢀ pointꢀ tubeꢀ andꢀ wereꢀ uncor‐
rected.ꢀElementalꢀanalysesꢀwereꢀconductedꢀusingꢀaꢀCarlo‐Erbaꢀ
EA1110ꢀCNNO‐Sꢀanalyzer,ꢀandꢀtheꢀresultsꢀagreedꢀwithꢀtheꢀcal‐
culatedꢀvalues.ꢀX‐rayꢀpowderꢀdiffractionꢀ(XRD)ꢀmeasurementsꢀ
wereꢀ performedꢀ usingꢀ aꢀ Philipsꢀ diffractometerꢀ withꢀ mono‐
ppm;ꢀ Anal.ꢀ calcd.ꢀ forꢀ C18
H
10
O ꢀ (%):ꢀ Cꢀ 83.71,ꢀ Hꢀ 3.90,ꢀ Oꢀ 12.39;ꢀ
2
found:ꢀCꢀ83.75,ꢀHꢀ3.88.ꢀ
2‐(2‐Formylphenyl)‐1‐naphthaldehydeꢀ (4b):ꢀ Yellowꢀ crys‐
−1
tals,ꢀm.p.ꢀ=ꢀ214–216ꢀ°C;ꢀIRꢀ(KBr):ꢀυꢀ(cm )ꢀ=ꢀ648,ꢀ709,ꢀ764,ꢀ831,ꢀ
954,ꢀ 1057,ꢀ 1196,ꢀ 1354,ꢀ 1429,ꢀ 1504,ꢀ 1591,ꢀ 1686,ꢀ 2754,ꢀ 2852,ꢀ
1
2926,ꢀ3057;ꢀ HꢀNMRꢀ(500ꢀMHz,ꢀCDCl
3
,ꢀ25ꢀ°C):ꢀδꢀ=ꢀ7.46ꢀ(d,ꢀJꢀ=ꢀ8.2ꢀ
Hz,ꢀ2H),ꢀ7.67–7.81ꢀ(m,ꢀ3H),ꢀ7.79ꢀ(t,ꢀJꢀ=ꢀ8.0ꢀHz,ꢀ1H),ꢀ8.01ꢀ(d,ꢀJꢀ=ꢀ
8.05ꢀHz,ꢀ1H),ꢀ8.15ꢀ(d,ꢀJꢀ=ꢀ8.3ꢀHz,ꢀ2H),ꢀ9.32ꢀ(d,ꢀJꢀ=ꢀ8.6ꢀHz,ꢀ1H),ꢀ
13
chromaticꢀCuꢀK
α
ꢀradiation.ꢀUltrasonicationꢀwasꢀperformedꢀinꢀaꢀ
9.92ꢀ(s,ꢀ1H),ꢀ10.23ꢀ(s,ꢀ1H)ꢀppm;ꢀ CꢀNMRꢀ(125ꢀMHz,ꢀCDCl ,ꢀ25ꢀ
3
Techno‐GazꢀTecnaꢀ3ꢀultrasonicꢀcleaner,ꢀwhichꢀsubjectedꢀsam‐
plesꢀtoꢀaꢀfrequencyꢀofꢀ50–60ꢀkHzꢀunderꢀaꢀtypicalꢀpowerꢀofꢀ250ꢀ
W.ꢀTheꢀreactionꢀflaskꢀwasꢀpositionedꢀwithinꢀtheꢀwaterꢀbathꢀofꢀ
theꢀultrasonicꢀcleanerꢀatꢀaꢀtemperature,ꢀcontrolledꢀbyꢀtheꢀde‐
vice.ꢀAnalyticalꢀgasꢀchromatographyꢀ(GC)ꢀevaluationꢀofꢀproductꢀ
°C):ꢀδꢀ=ꢀ126.26,ꢀ127.81,ꢀ128.95,ꢀ128.97,ꢀ129.15,ꢀ129.43,ꢀ130.18,ꢀ
130.28,ꢀ130.86,ꢀ132.55,ꢀ133.77,ꢀ133.91,ꢀ134.40,ꢀ134.97,ꢀ142.49,ꢀ
144.65,ꢀ 191.27,ꢀ 193.61ꢀ ppm;ꢀ Anal.ꢀ calcd.ꢀ forꢀ C18
H
12
O ꢀ (%):ꢀ Cꢀ
2
83.06,ꢀHꢀ4.65,ꢀOꢀ12.29;ꢀfound:ꢀCꢀ82.09,ꢀHꢀ4.66.ꢀ
Pyrene‐4,5‐dioneꢀ(5a):ꢀOrangeꢀcrystals,ꢀm.p.ꢀ=ꢀ299–302ꢀ°C;ꢀ
−1
mixturesꢀwasꢀperformedꢀonꢀaꢀgasꢀchromatographꢀ(split/
ꢀ
split‐
IRꢀ(KBr):ꢀυꢀ(cm )ꢀ=ꢀ703,ꢀ837,ꢀ1267,ꢀ1350,ꢀ1429,ꢀ1517,ꢀ1610,ꢀ
1
lessꢀ injector,ꢀ CPꢀ Silꢀ 8CBꢀ column,ꢀ FIDꢀ assembly;ꢀ Teifꢀ Gostarꢀ
FarazꢀCo.,ꢀIran).ꢀTransmissionꢀelectronꢀmicrographsꢀwereꢀob‐
tainedꢀusingꢀaꢀPhilipsꢀMC‐10ꢀtransmissionꢀelectronꢀmicroscopeꢀ
1663,ꢀ2850,ꢀ2923,ꢀ3068;ꢀ HꢀNMRꢀ(500ꢀMHz,ꢀCDCl
3
,ꢀ25ꢀ°C):ꢀδꢀ=ꢀ
7.52ꢀ(t,ꢀJꢀ=ꢀ7.6ꢀHz,ꢀ2H),ꢀ7.61ꢀ(s,ꢀ2H),ꢀ7.95ꢀ(d,ꢀJꢀ=ꢀ7.4ꢀHz,ꢀ2H),ꢀ8.18ꢀ
13
(d,ꢀJꢀ=ꢀ6.8ꢀHz,ꢀ2H)ꢀppm;ꢀ CꢀNMRꢀ(125ꢀMHz,ꢀCDCl
3
,ꢀ25ꢀ°C):ꢀδꢀ=ꢀ
(
TEM)ꢀemployingꢀanꢀaccelerationꢀvoltageꢀofꢀ80ꢀkV.ꢀBETꢀmeas‐
urementsꢀwereꢀacquiredꢀusingꢀaꢀSibataꢀsurfaceꢀareaꢀapparatusꢀ
100.ꢀInductivelyꢀcoupledꢀplasmaꢀanalysisꢀwasꢀconductedꢀonꢀaꢀ
Labtamꢀ8440ꢀPlasmaꢀLab.ꢀ ꢀ
127.52,ꢀ128.21,ꢀ128.44,ꢀ130.11,ꢀ130.21,ꢀ132.22,ꢀ136.04,ꢀ180.50ꢀ
ppm;ꢀ Anal.ꢀ calcd.ꢀ forꢀ C16
H
8
O ꢀ (%):ꢀ Cꢀ 82.75,ꢀ Hꢀ 3.47,ꢀ Oꢀ 13.78;ꢀ
2
1
found:ꢀCꢀ82.72,ꢀHꢀ3.45.ꢀ
Pyrene‐4,5,9,10‐tetraoneꢀ (6a):ꢀ Orangeꢀ crystals,ꢀ m.p.ꢀ >350ꢀ
−
1
°
C;ꢀIRꢀ(KBr):ꢀυꢀ(cm )ꢀ=ꢀ711,ꢀ808,ꢀ908,ꢀ1054,ꢀ1276,ꢀ1336,ꢀ1421,ꢀ
1
2
.4.ꢀ ꢀ UltrasoundꢀassistedꢀMCM‐41‐Ruꢀcatalyzedꢀoxidationꢀofꢀ
1446,ꢀ1562,ꢀ1676,ꢀ2923;ꢀ HꢀNMRꢀ(500ꢀMHz,ꢀDMSO‐d
6
,ꢀ25ꢀ°C):ꢀδꢀ