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1Author    H. Parlar, F. KorteRequires cookie*
 Abstract    Photokinetic experiments show that a series of chlorinated octahydro-1,4-endo, endo-5,8-dimethanonaphthaline (1-4) react intramole-cular and via tripletstate to their photoisomers (1 a-4a). The formation of the compounds 1 a-4a is dependent on oxygen and nature of sensitizers. 
  Reference    Z. Naturforsch. 35b, 1488—1490 (1980); eingegangen am 25. April 1980 
  Published    1980 
  Keywords    Cyclodiene Insecticides, Photoisomerization, Quantum Yields 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-1488_n.pdf 
 Identifier    ZNB-1980-35b-1488_n 
 Volume    35 
2Author    Heinz-Peter Schuchmann, Peter Naderwitz, Clemens Von SonntagRequires cookie*
 Title    Photolysis (A 185 nm) of Liquid Tetrahydropyran  
 Abstract    The main products of the 185 nm photolysis of neat liquid tetrahydropyran are pent-4-en-l-ol (7) (0 = 0.40), 2-(5'-hydroxypentyl)tetrahydropyran (10) (0.21), valeraldehyde (6) (0.13), and pentan-l-ol (8) (0.08). These products are thought to be formed via the bi-radical '0(0112)40112, and/or through intramolecular (6, 7, 8) and intermolecular (10) photoreactions. In the case of 10, the probability of a specific intermolecular photoreaction involving two tetrahydropyran molecules is suggested by the fact that in the photolysis of solutions of tetrahydropyran in cyclohexane and formaldehyde dimethyl acetal products analogous to 10 made up of a tetrahydropyran and a solvent molecule moiety, are not formed. 
  Reference    Z. Naturforsch. 33b, 942—945 (1978); received April 28 1978 
  Published    1978 
  Keywords    Photolysis, Tetrahydropyran, Quantum Yields, Biradical Intermediates, Photodimer 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0942.pdf 
 Identifier    ZNB-1978-33b-0942 
 Volume    33 
3Author    H. ParlarRequires cookie*
 Title    Konkurrenzreaktionen einiger tricyclischer Diene zur [2 2]PhotocycIoaddition Competitive Reaction of Some Tricyclic Dienes to [2+2]Photocycloaddition  
 Abstract    The UV-behaviour of some chlorinated tri-cyclic dienes (la-e) was studied in acetone. Cycloaddition (2a-b and 2d-c), hydrogen-transfer (3c' and 3d) and photo ene-(3c)-reaction products could be isolated and identified with the help of spectroscopic methods. 
  Reference    Z. Naturforsch. 34b, 363—365 (1979); eingegangen am 24. Oktober 1978 
  Published    1979 
  Keywords    UV Photolysis, Quantum Yields, Chlorinated Tricyclic Dienes 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-0363_n.pdf 
 Identifier    ZNB-1979-34b-0363_n 
 Volume    34 
4Author    Requires cookie*
 Title    The UV Photolysis (x = 185 n m ) o f Liquid Methyl rc-Propyl Ether  
 Abstract    H e i n z -P e t e r S c h u c h m a n n a n d Cl e m e n s v o n S o n n t a g Methyl The main products of the 185 nm photolysis of liquid methyl n-propyl ether (quantum yields in parentheses) are n-propanol (0.70), m ethane (0.29), «ec-butyl methyl ether (0.20), methanol (0.16), propionaldehyde (0.13), 3,4-dimethoxyhexane (0.09), ethane (0.08), and ethyl n-propyl ether (0.08). The quantum yields of further 24 minor products have been measured. The quantum yield of the sum of primary photochemical processes, the main ones of which are the homolytic scissions of the C -0 bonds (reactions i and ii), is close to unity. 
  Reference    (Z. Naturforsch. 30b, 399—403 [1975]; received January 27 1975) 
  Published    1975 
  Keywords    n-Propyl Ether, UV Photolysis, Quantum Yields, Radicals, Molecular Elimination Processes 
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 TEI-XML for    default:Reihe_B/30/ZNB-1975-30b-0399.pdf 
 Identifier    ZNB-1975-30b-0399 
 Volume    30 
5Author    Requires cookie*
 Title    Photolysis (A = 185 nm) of Liquid Acetaldehyde Dimethyl Acetal  
 Abstract    H e in z -P e t e r S c h u c h m a n n a n d C l e m e n s v o n S o n n t a g In stitut fü r Strahlenchemie im M ax-Planck-Institut für Kohlenforschung, Mülheim a. d. R uhr Deaerated liquid acetaldehyde dimethyl acetal has been photolyzed at X = 185 nm, and 28 products have been determined. The m ajor ones with their quantum yields are: methanol (0.59), methane (0.26), ethyl methyl ether (0.17), m ethyl vin yl ether (0.16), m ethyl form ate (0.14), ketene dimethyl acetal (0.1), ethane (0.06), hydrogen (0.06), and acetaldehyde (0.06). The m ajor prim ary processes are suggested to be the scission o f the C-OCH3 bonds (homolytic and molecular) and o f the O-CH3 bonds (homolytic). Minor processes are hydrogen elimination reactions and the scission o f the C-CH3 bond. 
  Reference    (Z. Naturforsch. 32b, 205 [1977]; received October 8 1976) 
  Published    1977 
  Keywords    UV, GC-MS, Quantum yields, Radical Reactions, Fragm entation Processes 
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 TEI-XML for    default:Reihe_B/32/ZNB-1977-32b-0205.pdf 
 Identifier    ZNB-1977-32b-0205 
 Volume    32 
6Author    Heinz-Peter Schuchmann, Heinz Bandmann, Clemens Von SonntagRequires cookie*
 Title    The 185 nm Photolysis of 1,4-Dioxane in the Liquid Phase  
 Abstract    The main products in the 185 nm photolysis of neat 1,4-dioxane are formaldehyde (0 = 0.25), glycol monovinyl ether (0.17), and ethylene (0.15). Some hydrogen (0.04), carbon monoxide (0.01), acetaldehyde (0.03), oxetane (0.04), and bidioxanyl (0.01) are also formed. On N20-saturation, the quantum yields of these products are diminished by about 30%, and N2 (0.59) and hydroxydioxane (0.4) become the main products. They are thought to be formed in the reaction sequence hv dioxane > • dioxane* dioxane* + N20 > • dioxane + N2 + O O + dioxane > • hydroxydioxane In aqueous dioxane, photoionisation is possible due to a greater lowering of the ionisa-tion threshold. In dioxane/water 20:80 the main products are H2 (0.50) and bidioxanyl (0.45), most likely formed in consequence of (dioxane)aq (dioxane)aq + eäq (dioxane)Jq • (dioxane-H)-+ H+ eäq + H+ > H-H-+ dioxane >-H2 + (dioxane-H)-2 (dioxane-H)- • bidioxanyl 
  Reference    Z. Naturforsch. 34b, 327—332 (1979); received October 6 1978 
  Published    1979 
  Keywords    Photolysis, 1, 4-Dioxane, Photoionisation, Energy Transfer, Quantum Yields 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-0327.pdf 
 Identifier    ZNB-1979-34b-0327 
 Volume    34 
7Author    Heinz-Peter Schuchmann, Clemens Von SonntagRequires cookie*
 Abstract    The photolysis of twelve aromatic ethers in solution has been studied by CIDNP and product analysis. The primary step is the scission of the C-O bond in the excited singlet state. The partners of the resulting radical pair (Ph-O" and R 1) undergo three major reactions: (i) geminate recombination and out-of-cage combination resulting in the reformation of the starting material, (ii) geminate recombination and out-of-cage combination resulting in cyclohexa-2,5-dienones and cyclohexa-2,4-dienones which are isomers of the starting material, (iii) H-abstraction from the solvent by the more reactive ones of the two radicals (mainly RO") and combination of the less reactive ones {e.g. benzyl) in the bulk solution. The quantum yield of photodecomposition is low for diphenyl ether (0 ~ 0.002) but approaches unity (0.3-0.9) in benzyl aryl ethers where the benzyl-oxygen bond is cleaved. If the aroxyl radicals are substituted in ortho (para) position the resulting ortho (para)-disubstituted cyclohexadienones are stable. Otherwise they swiftly rearrange into the phenols. The cyclohexa-2,4-dienones which are the precursors of the ortho-substituted phenols isomerize faster than the cyclohexa-2,5-dienones that give the para-substituted phenols. The rates of these rearrangement reactions are enhanced by acid catalysis. 
  Reference    Z. Naturforsch. 34b, 1002—1009 (1979); received February 23 1979 
  Published    1979 
  Keywords    !H NMR, Photo-CIDNP, Photolysis of Aryl Ethers, Keto-Enol Tautomers, Quantum Yields 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-1002.pdf 
 Identifier    ZNB-1979-34b-1002 
 Volume    34