"Green Photochemistry""Green Photochemistry"Solar PhotooxygenationsSolar Photooxygenations

with concentrated with concentrated SunlightSunlight

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Michael OelgemöllerMichael OelgemöllerChristian Jung, Jürgen Ortner, Elmar Christian Jung, Jürgen Ortner, Elmar

Zimmermann, Oliver Suchard, Jochen MattayZimmermann, Oliver Suchard, Jochen Mattay

"Back to the Roots""Back to the Roots"

2

sun, O2

Sens.

OO

Günther Otto Schenck (Heidelberg, ca. 1947)Giacomo Ciamician (Bologna, ca. 1910)

Martin Demuth (Mülheim, ca. 1995)Hans-Dieter Scharf (Almería, 1992)

sun, O2

Sens.O CHO O OHO

RoofsRoofs

H.D. Roth Angew. Chem. Int. Ed. Engl. 1989, 28, 1193.

M. Demuth et al. Pure Appl. Chem. 1998, 70, 2167.H.-D. Scharf et al. Angew. Chem. Int. Ed. Engl. 1994, 33, 2009.

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Solar Reactors at the German Aerospace CenterSolar Reactors at the German Aerospace Center

latitude: 50o51' N, 70 m above sea level - direct sunshine: 1500 h/a - direct insolation: 850 kWh/m2a

Parabolic Trough Facility for Organic Parabolic Trough Facility for Organic Photochemical Synthesis (PROPHIS)Photochemical Synthesis (PROPHIS)

CF: 32Aperture: max. 32 m2

Scale: 35-120 l

Compound Parabolic Collector (CPC)Compound Parabolic Collector (CPC)

CF: ca. 1Aperture: 3 m2

Scale: 35-60 l

Flat-Bed (PlexiglasFlat-Bed (Plexiglas© © or Makrolonor Makrolon©©, , Prof. Demuth, Mülheim / Ruhr)Prof. Demuth, Mülheim / Ruhr)

CF: 1Aperture: 1.5 m2

Scale: 20-25 l

Laboratory-Scale Parabolic Trough Laboratory-Scale Parabolic Trough Reactor Reactor

CF: 15Aperture: 0.2 m2

Scale: 0.2-1 l

Cologne 10.10.1995, 12:00 AM (calc.)

met

hyl

ene

blu

e

rose

ben

gal

S

200 300 400 500 600 700 800 900 1000

0.0

2.0x10-6

4.0x10-6

6.0x10-6

8.0x10-6

1.0x10-5

Wavelength [nm]

Ep

[m

olh

m-2s-1

nm-1]

extraterrestrial irradiance

Solarchemical Model-ReactionsSolarchemical Model-Reactions

4juglone

sunlight, 1O2

Rose Bengal

OH

OH

O

OH O

+1. sun, 1O2

OH OH OH OH

HO

2. Na2SO3

citronellol

1O2= 0.86

SSE0.54

1O2= 0.35

SSE0.37

O

O

OH

frenolicin B (R = Pr)kalafungin (R = Me)

O

O

O

R O

O

OH

K1115A(AP-I inhibitor)

Pr

CO2H

OH

OOH

nocardione A

O

O

O

O

OH

juglomycin A

OO

OH

O

O

urdamycinone B

OH

OOH

OHOHO

• versatile key-intermediate

Model Reaction I: Photooxygenation to JugloneModel Reaction I: Photooxygenation to Juglone

h

Rose Bengal

OH

OH

O

OH O

+ 1O2

lamp: 70-88%

500 g = 57.70 Euro 5 g = 94.50 Euro(165 times)

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• valuable target compound

• good yields with artificial light on multigram scales

(M. Oelgemöller et al. Tetrahedron 2006, 62, 1467.)

• thermal syntheses suffer from low yields, poor selectivity

and reproducibility and aggressive conditions

Sensitox®MB on Ion MB on Ion Exchange ResinExchange Resin

diol [g] Rose Bengal [g]

i-PrOH [ml] mirror area [m2]

time [h] yield [%] photons [mol]

1-2 0.1 200 0.2 3-8 65-79 2.3-7.4

Holographic mirrorHolographic mirror(550±140 nm)(550±140 nm)

sun, i-PrOH

Rose Bengal

OH

OH

O

OH O

+ 1O2

M. Oelgemöller et al. Green Chem. 2005, 7, 35.

Solar Chemical Reactions: August 2003Solar Chemical Reactions: August 2003

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conversion: 100%conversion: 100%yield: 79%yield: 79%after 3hafter 3h

Aluminum mirrorAluminum mirror

sun, i-PrOH

Rose Bengal

OH

OH

O

OH O

+ 1O2

Solar Chemical Reactions: August 2005Solar Chemical Reactions: August 2005

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conversions: >80%conversions: >80%yields: >60%yields: >60%after 4hafter 4h

M. Oelgemöller et al. Green Chem. 2006, submitted.

diol [g] Sensitizer [g]

i-PrOH [ml] mirror area [m2]

time [h] yield [%] photons [mol]

2 0.05-0.1 250 0.2 4 65-72 2.0-2.8

24 g diol

3000 ml i-PrOH

conversion: 48%

after ca. 11 h

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Model Reaction II: Photooxygenation of CitronellolModel Reaction II: Photooxygenation of Citronellol

+1. h, 1O2

OH OH OH OH

HO

2. Na2SO3

H+

O

rose oxidecitronellol lamp (MeOH): 35% 60%

9 kg = 127.70 Euro 1 kg = 157.65 Euro(11 times)

• valuable target compound

• good yields with artificial light on multigram scales

(G. Ohloff et al. Angew. Chem. 1961, 73, 578.)

• thermal syntheses difficult and much more expensive

Symrise (Holzminden, Germany): ca. 100 t/a

small scale large scale

25 kg citronellol 200 kg citronellol

75 kg MeOH 600 kg MeOH

3 lamps à 2000 W 6 lamps à 2000 W

2 days 1.5 - 2 days

10 kg rose oxide 70 kg rose oxide

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Solar Chemical Reaction: September 2002Solar Chemical Reaction: September 2002

M. Oelgemöller et al. Green Chem. 2005, 7, 35.

conversion: 100%conversion: 100%ratio: 45:55ratio: 45:55ca.ca. 2.5 h 2.5 h

PROPHISPROPHIS

+1. h, 1O2

OH OH OH OH

HO

2. Na2SO3

H+

O

rose oxidecitronellol ratio: 45% 55%54%

(99%)

conversions: 100%perfect insolation: 7 hpoor insulation: ca. 30 h

CPCCPC (40 l)

conversions: 100/65%perfect insolation: 12 hpoor insulation: 33 h

horizontal tube reactorhorizontal tube reactor (25 l)

conversions: 100%perfect insolation: 15 hpoor insulation: 30 h

Flat-bedFlat-bed(21 l)

PROPHIS PROPHIS (80 l)

conversion: 100%perfect insolation (Sep.): 2.5 hpoor insulation (Oct.): n.o.

vertical tube reactorvertical tube reactor (20 l)

conversions: 100/65%perfect insolation: 13 hpoor insulation: 33 h10 vol-% citronellol in isopropanol, 0.5 g rose bengal / l isopropanol

+1. h, 1O2

OH OH OH OH

HO

2. Na2SO3

04:00 08:00 12:00 16:00 20:000

200

400

600

800

1000

Time (CESR)I g

(51o ) [

W m

-2]

14.7.2003 12.9.2002 12.9.2000

04:00 08:00 12:00 16:00 20:000

200

400

600

800

1000

Time (CESR)

I n [W

m-2]

14.7.2003 12.9.2002 12.9.2000

PROPHISPROPHIS CPC/Flat-bed/tube reactorsCPC/Flat-bed/tube reactors

direct radiation only(direct normal irradiance In)

direct and diffuse radiation(global horizontal irradiance Ig51O)

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Solar Chemical Campaign: September/October 2002Solar Chemical Campaign: September/October 2002

"On the arid lands there will spring up industrial

colonies without smoke and without smokestacks,

forests of glass tubes will extend over the plains, and

glass buildings will rise everywhere; inside of these will

take place the photochemical processes that hitherto

have been the guarded secret of the plants, but have

been mastered by human industry which will know how

to make them bear even more abundant fruit than nature,

for nature is not in a hurry and mankind is."

(Giacomo Ciamician Science 1912, 36, 385.)

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FundingFunding