Dedicated t o P r o f . Dr. K a r l K r a t e l ABSTRACT C h a r g e -t r a n s f e r complexes were found t o o c c u r between k r a f t l i g n i n and a n added model quinone, 3 , 5 -d i -~-b u t y 1 -1 , 2 -b e n z o q u i n o n e . The o c c u r r e n c e of c h a r g e -t r a n s f e r i n t e r a c t i o n s was a l s o a p p a r e n t i n an o x i d i z e d k r a f t l i g n i n w i t h a n i n c r e a s e d quinone c o n t e n t . I n t h e s e systems, f r e e p h e n o l i c groups w i t h i n t h e l i g n i n were cons i d e r e d t h e donor s p e c i e s and ortho-quinones t h e complementary a c c e p t o r m o i e t i e s . Carbon-I4 l a b e l i n g r e v e a l e d t h a t t h e quinone c o n t e n t of t h e i n v e s t i g a t e d k r a f t l i g n i n averaged 3%. These q u i n o n e s were determined t o have a molar a b s o r p t i v i t y of 528 L/mol-cm. Upon sodium borohydride r e d u c t i o n of t h i s l i g n i n , o n l y o n e -t h i r d of t h e absorbance d e c r e a s e c o u l d be accounted f o r by t h i s number of quinones. The remaining t w o -t h i r d s of t h e d e c r e a s e i n absorbance was a s s i g n e d t o t h e d i s r u p t i o n of c h a r g e -t r a n s f e r complexes. The quinones, t h e r e f o r e , played a d u a

Chelation and removal of transition metals from the kraft lignin employed in this study did not reduce the lignin's visible absorbance.Likewise, hydrogenation of carbon-carbon double bonds in this lignin also had no effect on its visible spectrum. This indicated that extended conjugated systems were not a significant contributor to the color of this lignin. Of the structures investigated, quinones were found to be the major visible-light absorbing chromophores. Since a large component of the quinone's absorption results 1 from their participation in charge-transfer complexes (CTC's), CTC's were a significant contributor to the color of this lignin.

During the drying and pyrolysis phases of kraft black liquor combustion, significant swelling of individual liquor particles occurs. Swollen volumes can reach 20 to 30 times the original volume during combustion. The swelling process can conceivably affect the combustibility of black liquor and the amount of carryover in a recovery furnace.The composition of black liquor was found to have a large influence on swelling. A combination of sugar acids and kraft lignin swelled to a larger extent than when either component was pyrolyzed separately. A 1:1 ratio of these two components resulted in maximum swelling for the various ratios tested. The molecular weight of kraft lignin had an effect on swollen volume with higher molecular weight fractions producing lower swelling chars.Other components were found to reduce the swelling of black liquors. Extractives interfered with the swelling by appearing to change the deformable properties of the pyrolyzing material. Inorganic salts acted as a diluent.Analysis of the surface characteristics of chars revealed that good swelling chars were composed of small bubbles 50 to 150 microns in diameter. Poor swelling liquors did not exhibit this phenomenon. The formation of bubbles was found to be initiated at 240°C, which closely corresponded to the thermal decomposition temperature of a sugar acid. Kraft lignin appeared to have a major influence on the viscous properties of the pyrolyzing particle. The composition of black liquor determines to a large extent the surface active and viscous forces present in black liquor; these forces are believed to be responsible for the extent to which kraft black liquors deform and swell during pyrolysis.

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Die Friedel-Crafts-Reaktion von 0-Acylsalicyloylchloriden mit reaktiondahigen Aromaten und aromatischen Heterocyclen fuhrt unter dem katalytischen EinfluD von Zinn(IV)-chlorid zu 2-Alkyl-2-aryl-1,3-bcnzodioxan4onen (6). Durch Verfolgung der Reaktion mittels Protonenresonanzspektroskopie konnte das intermediar gebildete cyclische Acetoxonium-Ion 4 der Salicylsiiure nachgewiesen werden. Die Kinetik der Bildung dieses Ions aus 0-Acetylsalicyloylchlorid und Zinn(1V)-chlorid wurde auch in Abwesenheit eines nucleophilen Reaktionspartners mittele zeitabhangiger NMR-Spektroskopie untersucht. Preparation of 2-AUryI-Zaryl-l&benzodioxan4onw by Friedel-Cnfb Reaction of 0-Acylsalkyloyl Cbloridw and AromatesFriedel-Crafts reaction of 0-acylsalicyloyl chlorides with reactive aromates and aromatic heterocycles yields under the catalytic influence of stannic chloride 2-alkyl-2-aryl-1,3-beenzodioxanCones (6). Following the reaction by proton resonance spectroscopy the intermediarily formed cyclic acetoxonium ion 4 of salicylic acid could be verified. The kinetics of the formation of this ion from 0-acetylsalicyloyl chloride and stannic chloride was investigated by means of timedependent n.m.r. spectroscopy even in the absence of a nucleophile.

Die Friedel-Crafts-Reaktion von o-Acetylbenzoylchlorid (1 b) rnit reaktionsfahigen Aromaten und aromatischen Heterocyclen fuhrt in Gegenwart von Zinn(1V)-chlorid zu 3-Aryl-3-methylphthaliden (2d -f, 5). Bei der Umsetzung von o-Hydroxyacetophenon (Sa) rnit Phosgen entsteht nicht Chlorameisensaure-(2-acetyIphenylester) (8 b), sondern 4-Methylen-4H-l,3-benzodioxin-2-on (7). Diem reagiert mit Resorcin-dimethylether (3) unter Friedel-Crafts-Bedingungen unter C0,-Eliminierung zu 2-[1-(2,4-Dimethoxyphenyl)vinyl]phenol(9a). Im Falle der o-Acetonylbenzoesaure (11) erhielt man weder rnit Thionylchlorid das Saurechlorid, noch eine Friedel-Crafts-Reaktion rnit reaktiven Aromaten, sondern in allen Fallen entstand lediglich 3-Methylisocumarin (12). Investigations on the Behnviour of the Chlorides of cCarbonyl Compounds of Benzoic and Phenoxyformic Acids in Friedel Crafts ReactionsFriedel Crafts reaction of o-acetylbenzoyl chloride (I b) with reactive arenes and aromatic heterocycles in the presence of stannic chloride yields 3-aryl-3-methylphthalides (26f, 5). Treatment of o-hydroxyacetophenone @a) with phosgene does not lead to chloroformic 2-acetylphenyl ester (8b) but to 4-methylene-4H-l,3-benzodioxin-2-one (7). Friedel Crafts reaction of 7 with resorcinol dimethyl ether (3) results in elimination of C 0 2 and formation of 2-[1-(2,4dimethoxyphenylk vinyl]phenol(9a). o-Acetonylbenzoic acid (11) did not give the acyl chloride with thionyl chloride, nor did it react with active arenes under Friedel Crafts conditions. In all cases only 3-methylisocoumarine (12) was formed.Die Ring-Ketten-Tautomerie der o- Acetylbenzoesaure (1 a, 2a) sowie von deren Substitutionsprodukten in &Stellung wurde anhand von IR-'), UVund Kernresonanzspektren l S 2 ) untersucht. Die beobachteten Substituenteneffekte sowie die Einfliisse der Polaritaten der Losungsmittel auf die Konstitutionen entsprachen den zu erwartenden Ergebnissen.Bei der Umsetzung von l a rnit Thionylchlorid erhielten Halford und Weissmunn3) als einziges Produkt o-Acetylbenzoylchlorid (1 b). Nach eigenen Untersuchungen mittels Kernresonanzspektroskopie lie@ aber eine ungefahr aquimolare Mischung zweier Substanzen vor, deren Schmelzbereich mit dern in der Literatur angefuhrten Schmelzpunkt