CHM 2202 Spring 2010 Department of Chemistry Organic Chemistry Lab II Villanova University Page 1 of 3 Chemilumines c e n c e!Modified!Experimental!Procedure!from!Bell,!Clar k!and!Taber,!pgs!261"262!!Caution:!!Carry!out!Part!A!in!your!hood.!!Oxalyl!chloride!is!t o x i c!and!a!lachrymator!(a!tear!gas).!!Do!not!breathe!its!vapors!since!it!hydrolyzes ! to!HCl!in!moist!environ m e n ts!and! ca n! cause! lung! damage! if! inhaled.! ! 2,4"Dinitrophenol! is! toxic! and!c an! cause! skin!burns.!!Wear!gloves!fo r !this!experiment.!!A.!!Preparation!of!Bis"(2,4"Dinit r ophenyl)!Oxalate! OH+ClOClOOOOO2 (C2H5)3NMW = 184.11Oxalyl chlorideMW = 126.93Wt: 0.045 g (0.35 mmol)MW = 101.19MW = 422.23Wt: 0.12 g (0.65 mmol)2Wt: 0.1mL (0.72 mmol)+2(C2H5)3N HClNO2NO2O2NNO2NO2NO2 1. Prepare!and!have!re ady!a!warm!wate r!bath!(~75!" !80°!C)!for!use!in!Step!10.!!!2. Add!0.12!g!of!dry!2, 4"dinitrophenol!to!a!dry!centrifuge!tube.!3. Add!0.6!mL!of!reagent" g r a d e!dry!acetone!to!the!centrifuge!tube !and!swirl!to!diss olve!the!phenol!4. To! this! phenol! solution! add! 0.1! mL! of! pure! reagent! grade! triethylamine! (not! the! 10% !triethylamine!in!dimethyl!phthalate)!and!cool!the!resulting!solution!in!an!ice!bath.!!(DO!NOT!ALLOW!W ATER!TO!GET!INTO!THE!REACTION!MIXTURE)!5. IN!THE!HOOD,!add!DROPWISE!and!with!constant!s tirring!(use!a!glass!rod)!0.1!mL!(0.045 !g)! of! a! 30% ! (v/v)! solution! of! oxalyl! chloride! in! methyl! tert"butyl! ether! to! the! cooled!phenol!solution.!!A!precipitate!will!form!during!the!addition.!!Try!to!make!sure !that!the!oxalyl!chloride!solution!goes!directly!into!the!solution!and!that!it!does!not!hit!the!sides!of!the!test!tube!or !t he!stirring!rod!as!you!are!adding!it.!!!6. Continue!to!s tir!the!cooled!reaction!mixtur e !until!it!is!a!thick!cream!colore d!suspension.!7. When! the! precipitate! d oes! not! a ppear! to! be! getting! thicker,! back"titrate! by! adding! 1!drop!of!triethylamine!to!the!mi xture.!8. If! a! yellow/orange! color! develops! (this! indicates! the! presence! of! unreacted! starting!phenol),!add!an!additional!0.05!mL!(1!or!2!drops)!of!oxalyl!chloride!(NO!MORE! THAN! 2 !DROPS!!)! to! the! cooled! (ice! bath)! mixture! with! stirr i ng! and! the! yellow/orange! col or!should!disappe a r.!9. NOTE:! ! It! is ! important! to! keep! the! reaction! mixture! cold! during! the! above!manipulations)!10. After! 10! minutes! of! stirri n g,! warm! the! mix t u re! gently! for! 5! –! 10! minutes! using! a! hot!water! bath! (75! "! 8 0°!C)! and! stir! the! contents! in! the! tube! with! a! glass! rod! to! evaporate!most!of!the!aceto ne.!!!11. When!the!acetone!is!evap orated,!the!remaining!solid!should!be!dry!and!flakey;!remove!the! material! [bis"( 2,4"dinitrophenyl)!oxalate]! from! th e! centrifuge! tube! with! a! spatula!and! allow! it! to! ai r ! dry.! ! Creamy! yellow! or! tan ! crystals! provide! the! b est! light! in! the!following!par t!of!the!experiment.!!If!you!do!n ot!get!nice!looking!material,!you!may!want!to!consider!re ru nn i ng!this!firs t!pa rt!of!the!experiment!since!it!is!easy !to!do.!!Last!year,!!CHM 2202 Spring 2010 Department of Chemistry Organic Chemistry Lab II Villanova University Page 2 of 3 !some! groups! ran! this! part! of! the! reaction! several! times ! until! suitabl e! material! was!obtained.!12. Use!this!dry!material!in!t he!next!step!of!this!experiment.!!B.!!!Chemiluminescence! 1. Label! 5! te st! tubes! to! indicate! each! of! the! flu orescent! emi t ter s ! (Acceptors)! that! w i l l! be!used.! ! The! emitters! are! 0.002! M! soluti o ns! (in! dimethyl! phthalate)! of! the! following!compounds:!o 9,10"Diphenylan t h r ac ene!o Rubrene!o 2,3"Benzanthracene!(also!known !a s!Benz(b)an thracene!or!Naphthacen e)!o Rhodamine!B!o Rhodamine!G!(aka!Rhodamine!6G)!2. Place!1!mL!of!the!0.002!M!emitter!solutions!into!t he!appropriately!labeled!tes t!tubes.!3. To!each!of!the!test!tubes!con t a ining!the! e m i t t e r!solutions,!add!1!mL!of!a!0.2!M!solution!of!hydrogen!p e ro x i d e!in!dimethyl!phthalate/t"butyl!alcohol.!4. Swirl!the!test!tubes!to !mix!the!solution s!thoroughly.!5. Take! the!test! t u b e s ,!your!notebook!and!your!container!of!bis"(2,4"dinitroph en y l)!oxalate!(prepared! above! in! Pa rt! A.)! to! a! dark! area! of! the! room.! ! Use! TLC! light! boxes,! lockers,!cabinets,!etc.!!Some!of!the! lab! ligh ts!will!be!turned!off!to!help!create!dark!areas! of!the!lab.!6. Add! a! few! crystals! of! the! bis"(2,4 " d i n itrophenyl)! o xalate! (prepared! in! Part! A)! to! each!tube! in! a! dark! area! and! record! your! observatio ns.! ! Be! sure! to! thoroughly! an d!immediately!swirl!the!tub es!im m ediately!after!adding!the!oxalate;!this!will!ensure!that!you!obtain!the!st r ongest!light!em i ssion.!!Record!the!color!and!in t ensity!of!light!emitted.!!To!observe!the!effec t!of!added!base!on!the!chemiluminescence!r e action!!1. Mix! 2! mL! of! 0.002! M! 9,10"diphenylanthracene! sol ution! and! 2! mL! of! 0.2! M! hydroge n!peroxide!in!a! s i n g le!test!tube.!!Swir l !the!tube!to! m ix!thoroughly.!2. Remove!half!of!this!mixtu re!and!place!it!in!another!test!tube!so! you!now!have! two!tubes!containing!2!mL!each!of!the!hydrogen!peroxide/9,10"dipheny lanthracene!solution.!CHM 2202 Spring 2010 Department of Chemistry Organic Chemistry Lab II Villanova University Page 3 of 3 !!!3. In!another!labeled!test!tube,!dissol ve!several!mg!of!your!diaryloxalate!(prepare d! ab ove!in!Part!A)!in!2!mL!of!dimethyl!pht h alate!(located!in!the!community!hood).!4. And! finally,! in! another! labeled! test! tube,! place! a! few! drops! of! the! 10%! solution! of!triethylamine! in! dimethyl! phthalate! (do! not! use! the! pure! triethyla m i n e ! reagent!)! to!have! it! rea dy! for! use! in! Step! 6 .! ! Keep! a! disposable! pipette! with! this! solutio n ! since! you!will!need!it!later !in!the!exper i me nt.!5. In!a!dark!ar ea!add!at!the!same!time!1!mL!of!the!diar y l oxalate!solutio n!(prepared! in!Step!3)! to! each! of! the! tubes! containing! the! 9,10"diphenylanthracene/hydrogen! peroxide!mixture! (prepared! in! Step! 2)! and! swirl/shake! the! tubes! briefly! (3! seconds)! to! obtain! a!chemiluminescence! reaction.! ! Keep! the! tubes! side! by! side! so! you! can! compare! them.!!NOTE:!!Be!ready!to!immediately!proc eed!to!Step!6!before!the!light!fades!!6. Quickly!add!a!drop! of!the!10%!triethylamine!solution!(from!Ste p!4)!to!one!tube,!shake!it,!and! compare! the! light! emanati ng! from! the!