The careful X-ray examination of naphtalene by Robertson et al. allowed a detailed comparison of calculated bond lengths with experimental ones. The underlying idea of the present investigation was to give a similar comparison for a polyene compound consisting of a chain of alternating single and double bonds. ...

Zie: Summary

Drenth, Wiendelt,

The careful X-ray examination of naphtalene by Robertson et al. allowed a detailed comparison of calculated bond lengths with experimental ones. The underlying idea of the present investigation was to give a similar comparison for a polyene compound consisting of a chain of alternating single and double bonds. ... Zie: Summar

Drenth, Wiendelt

ARTS repository - University of Groningen

   University of GroningenAtoomafstanden in α,ω-Diphenyl-polyenenDrenth, WiendeltIMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:1956Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):Drenth, W. (1956). Atoomafstanden in α,ω-Diphenyl-polyenen. Excelsior.CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 09-09-2023S U M M A R YThe carefur  x- ra l  examinat ion of  naphta lene by Robertson eta l .  a t lowed a deta i led compar i -son of  ca. lcu lated bond Iengths wi thexper imenta l  ones.  The under ly ing idea of  the present  invest iga-tion was to give a similar cornparison for a polyene compound con-s is t ing of  a chain of  a l ternat ing s ingle and doubl 'e  bonds.  l '4o lec-u la r  o rb i t a l  ca l cu la t i ons  by  Cou l son  p red i c ted  a  cons ide rab ledecrease of  the lengths of  the s ingle bonds and sone increase ofthe lengths of  the double bonds,  especia l ly  in  the centre of  thechains.  Unsubst i tu ted polyenes are unstable and hence less sui t -able for  an X-rw'  examinat ion,  The a,r , : 'd iphenyl -conpounds,  how-ever ,  are crysta l l ine and stable at  room.temperature.  The ct ,urd i -phenyl -polyenes were therefore chosen for  the present  invest iga-tion.The resul ts  of  molecular  orb i ta l  ca lculat ions on the ser ies ofcr ,odiphenyl -polyenes,  Ph-(CH=CH-) .Ph wi th n = 0 -  5 are g iven lnchap te r  3 .  I n  add i t i on  t o  t he  a tom ic  d i s tances  the  ene rg ies  o fthe molecular  orb i ta ls  were calculated.  Eeni-empir ica l  va lues forthe exchange integra l  B were deduced f rom a compar ison of  ca lcu-lated wi th observed resonance energies and e lect ronic  t ransi t ionenergies.  The molecular  orb i ta l  ca lculat ions on b i .phenyl ,  s t i t -bene and d iphenyl -butadiene were extended to a second order  ap-p rox ima t i on ,  i n  wh i ch  the  va r i a t i on  o f  p  w i t h  d i s tance  was  i n -t r oduced .  The  e f f ec t  o f  t h i s  va r i a t i on  on  the  ca l cu la ted  bonddistances was snal l .Sone crysta l lographic propert ies of  the members of  the ser iesw i th  n  - -  2  -  5  a re  desc r i bed  i n  chap te r  5 .  Each  o f  t hese  com-pounds  can  c rys ta l l i ze  i n  an  o r tho rhomb ic  and  i n  a  monoc l i n i cmodi f icat ion.  The or thorhombic nodi . f icat ion is  the most  s tableone at  and above room-temperature.  These or thorhombic modi f ica-t ions const i tu te a homologous ser ies as do the nronocl in ic  modi f l -cat ions of  the terns n = 3,  4 and 5.  The or ientat ions of  the mol-ecules in  the or thorhombic and ln the monocl in ic  crysta ls  appearf rom the st ructure analyses of  1,  10-d iphenyl -  1,  3,  5,  ?,9-decapen-taene  ( chap te r  6 ) .  These  o r i en ta t i ons  we re  found  by  b r i a l  anderror, naking use of the change of the lattice constants observedin  t h i s  se r i es  o f  compounds  and  o f  t he  op t i ca l  p rope r t i es .  The107co-ord lna, tes of  the carbn atoms were ref ined by Fbur ier  pro jec-tions. The available crystals iyere rather thin, however, and con-sequently the nunber of obseryod reflections was small. The expe-r i . nen ta l  bond  l eng tbs  we re  sub jec t  t o  a  s tanda rd  dev i . a t i on  o fapproxinate ly  0,03 & Therefore a deta i led compar ison of  observedwl th calculated bond lengths is  not  possib le.Thicker ,  wel l -developed or thorhombic crysta ls  of  1,8-d iphenyl -1,3,5,?-octatet raene were avai lable.  These crysta ls  were used foran X-ray structure determination described j.n chapter 7. In orderto  i nc rease  the  number  o f  obse rvab le  re f l ec t i ons  t he  c r ys ta l swere  coo led  down  to  -100oC by  means  o f  a  s t ream o f  evapo ra tedI i qu i . d  a i r .  A I I  h  &  I  r e f l ec t i ons  obse rved  w i th in  t he  reg ion  o fcopper radi .at ion were used for  tbe st ructure determinat ion.The  no lecu les  possess  a  cen t re  o f  symmet ry .  S ta r t j ' ng  f r om ase r i es  o f  app rox ima te  co -o rd ina tes ,  f ound  by  two -d j .mens iona lmethods,  the s igns of  the observed h k I  s t ructure factors werecalculated and used in a three-dimensional  Fbur ier  synthesis  oft he  e lec t ron  dens i t y  d i s t r i bu t i on  t h roughou t  t he  un i t  ce I I .  Thecarbon atoms of  the polyene chain are located in  a p lane,  as arethe atoms of  a pherv l  group.  These two p lanes make an angle of5,4"  wi th each other .  The hydrogen atoms are c lear ly  v j .s ib le inthe e l .ect ron densi ty  sect ions according to these p lanes.A f ina l  ref inement  of  the 'co-ord inates of  the carbon atoms wasobta ined by comput ing two d i f ferent ia l  syntheses;  in  one of  themthe observed and in the other  one the calculated st ructure fac-tors were used.  The standard deviat ion of  the exper imenta l  bondIengths arnounted to 0,004 E.There is  not  a c lose agreement  between calculated and observedbond  l eng ths  i n  d ipheny l -oc ta te t raene .  The  Ieng ths  o f  t he  C -Csingle bonds of  the polyene chain are s igni f icant l .y  snal ler  thanthe length of  a t rue s ingle bond,  but  the d i f ferences are not  aslarge as Dredicted theoret ica l ly .  The calculated increase of  the]engths of  the double bonds j .n  the chain wj . th  respect  to  a t ruedouble bond appears hard ly  or  not  at  a l l .  The C-C bonds of  the,po l yene  cha in  con ta in  ang les  o f  app rox ima te l y  124 " ,  bu t  two  o ft hese  ang les  a re  i nc reased  to  L27 " ,  p robabJ ,y  due  to  a  mu tua lrepul.sj-on of hydrogen atoms.l0B

English

Atoomafstanden in α,ω-Diphenyl-polyenen

   University of GroningenAtoomafstanden in α,ω-Diphenyl-polyenenDrenth, WiendeltIMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:1956Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):Drenth, W. (1956). Atoomafstanden in α,ω-Diphenyl-polyenen. Excelsior.CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 08-06-2022S U M M A R YThe carefur  x- ra l  examinat ion of  naphta lene by Robertson eta l .  a t lowed a deta i led compar i -son of  ca. lcu lated bond Iengths wi thexper imenta l  ones.  The under ly ing idea of  the present  invest iga-tion was to give a similar cornparison for a polyene compound con-s is t ing of  a chain of  a l ternat ing s ingle and doubl 'e  bonds.  l '4o lec-u la r  o rb i t a l  ca l cu la t i ons  by  Cou l son  p red i c ted  a  cons ide rab ledecrease of  the lengths of  the s ingle bonds and sone increase ofthe lengths of  the double bonds,  especia l ly  in  the centre of  thechains.  Unsubst i tu ted polyenes are unstable and hence less sui t -able for  an X-rw'  examinat ion,  The a,r , : 'd iphenyl -conpounds,  how-ever ,  are crysta l l ine and stable at  room.temperature.  The ct ,urd i -phenyl -polyenes were therefore chosen for  the present  invest iga-tion.The resul ts  of  molecular  orb i ta l  ca lculat ions on the ser ies ofcr ,odiphenyl -polyenes,  Ph-(CH=CH-) .Ph wi th n = 0 -  5 are g iven lnchap te r  3 .  I n  add i t i on  t o  t he  a tom ic  d i s tances  the  ene rg ies  o fthe molecular  orb i ta ls  were calculated.  Eeni-empir ica l  va lues forthe exchange integra l  B were deduced f rom a compar ison of  ca lcu-lated wi th observed resonance energies and e lect ronic  t ransi t ionenergies.  The molecular  orb i ta l  ca lculat ions on b i .phenyl ,  s t i t -bene and d iphenyl -butadiene were extended to a second order  ap-p rox ima t i on ,  i n  wh i ch  the  va r i a t i on  o f  p  w i t h  d i s tance  was  i n -t r oduced .  The  e f f ec t  o f  t h i s  va r i a t i on  on  the  ca l cu la ted  bonddistances was snal l .Sone crysta l lographic propert ies of  the members of  the ser iesw i th  n  - -  2  -  5  a re  desc r i bed  i n  chap te r  5 .  Each  o f  t hese  com-pounds  can  c rys ta l l i ze  i n  an  o r tho rhomb ic  and  i n  a  monoc l i n i cmodi f icat ion.  The or thorhombic nodi . f icat ion is  the most  s tableone at  and above room-temperature.  These or thorhombic modi f ica-t ions const i tu te a homologous ser ies as do the nronocl in ic  modi f l -cat ions of  the terns n = 3,  4 and 5.  The or ientat ions of  the mol-ecules in  the or thorhombic and ln the monocl in ic  crysta ls  appearf rom the st ructure analyses of  1,  10-d iphenyl -  1,  3,  5,  ?,9-decapen-taene  ( chap te r  6 ) .  These  o r i en ta t i ons  we re  found  by  b r i a l  anderror, naking use of the change of the lattice constants observedin  t h i s  se r i es  o f  compounds  and  o f  t he  op t i ca l  p rope r t i es .  The107co-ord lna, tes of  the carbn atoms were ref ined by Fbur ier  pro jec-tions. The available crystals iyere rather thin, however, and con-sequently the nunber of obseryod reflections was small. The expe-r i . nen ta l  bond  l eng tbs  we re  sub jec t  t o  a  s tanda rd  dev i . a t i on  o fapproxinate ly  0,03 & Therefore a deta i led compar ison of  observedwl th calculated bond lengths is  not  possib le.Thicker ,  wel l -developed or thorhombic crysta ls  of  1,8-d iphenyl -1,3,5,?-octatet raene were avai lable.  These crysta ls  were used foran X-ray structure determination described j.n chapter 7. In orderto  i nc rease  the  number  o f  obse rvab le  re f l ec t i ons  t he  c r ys ta l swere  coo led  down  to  -100oC by  means  o f  a  s t ream o f  evapo ra tedI i qu i . d  a i r .  A I I  h  &  I  r e f l ec t i ons  obse rved  w i th in  t he  reg ion  o fcopper radi .at ion were used for  tbe st ructure determinat ion.The  no lecu les  possess  a  cen t re  o f  symmet ry .  S ta r t j ' ng  f r om ase r i es  o f  app rox ima te  co -o rd ina tes ,  f ound  by  two -d j .mens iona lmethods,  the s igns of  the observed h k I  s t ructure factors werecalculated and used in a three-dimensional  Fbur ier  synthesis  oft he  e lec t ron  dens i t y  d i s t r i bu t i on  t h roughou t  t he  un i t  ce I I .  Thecarbon atoms of  the polyene chain are located in  a p lane,  as arethe atoms of  a pherv l  group.  These two p lanes make an angle of5,4"  wi th each other .  The hydrogen atoms are c lear ly  v j .s ib le inthe e l .ect ron densi ty  sect ions according to these p lanes.A f ina l  ref inement  of  the 'co-ord inates of  the carbon atoms wasobta ined by comput ing two d i f ferent ia l  syntheses;  in  one of  themthe observed and in the other  one the calculated st ructure fac-tors were used.  The standard deviat ion of  the exper imenta l  bondIengths arnounted to 0,004 E.There is  not  a c lose agreement  between calculated and observedbond  l eng ths  i n  d ipheny l -oc ta te t raene .  The  Ieng ths  o f  t he  C -Csingle bonds of  the polyene chain are s igni f icant l .y  snal ler  thanthe length of  a t rue s ingle bond,  but  the d i f ferences are not  aslarge as Dredicted theoret ica l ly .  The calculated increase of  the]engths of  the double bonds j .n  the chain wj . th  respect  to  a t ruedouble bond appears hard ly  or  not  at  a l l .  The C-C bonds of  the,po l yene  cha in  con ta in  ang les  o f  app rox ima te l y  124 " ,  bu t  two  o ft hese  ang les  a re  i nc reased  to  L27 " ,  p robabJ ,y  due  to  a  mu tua lrepul.sj-on of hydrogen atoms.l0B

University of Groningen

   University of GroningenAtoomafstanden in α,ω-Diphenyl-polyenenDrenth, WiendeltIMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:1956Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):Drenth, W. (1956). Atoomafstanden in α,ω-Diphenyl-polyenen. Groningen: Excelsior.CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 12-11-2019S U M M A R YThe carefur  x- ra l  examinat ion of  naphta lene by Robertson eta l .  a t lowed a deta i led compar i -son of  ca. lcu lated bond Iengths wi thexper imenta l  ones.  The under ly ing idea of  the present  invest iga-tion was to give a similar cornparison for a polyene compound con-s is t ing of  a chain of  a l ternat ing s ingle and doubl 'e  bonds.  l '4o lec-u la r  o rb i t a l  ca l cu la t i ons  by  Cou l son  p red i c ted  a  cons ide rab ledecrease of  the lengths of  the s ingle bonds and sone increase ofthe lengths of  the double bonds,  especia l ly  in  the centre of  thechains.  Unsubst i tu ted polyenes are unstable and hence less sui t -able for  an X-rw'  examinat ion,  The a,r , : 'd iphenyl -conpounds,  how-ever ,  are crysta l l ine and stable at  room.temperature.  The ct ,urd i -phenyl -polyenes were therefore chosen for  the present  invest iga-tion.The resul ts  of  molecular  orb i ta l  ca lculat ions on the ser ies ofcr ,odiphenyl -polyenes,  Ph-(CH=CH-) .Ph wi th n = 0 -  5 are g iven lnchap te r  3 .  I n  add i t i on  t o  t he  a tom ic  d i s tances  the  ene rg ies  o fthe molecular  orb i ta ls  were calculated.  Eeni-empir ica l  va lues forthe exchange integra l  B were deduced f rom a compar ison of  ca lcu-lated wi th observed resonance energies and e lect ronic  t ransi t ionenergies.  The molecular  orb i ta l  ca lculat ions on b i .phenyl ,  s t i t -bene and d iphenyl -butadiene were extended to a second order  ap-p rox ima t i on ,  i n  wh i ch  the  va r i a t i on  o f  p  w i t h  d i s tance  was  i n -t r oduced .  The  e f f ec t  o f  t h i s  va r i a t i on  on  the  ca l cu la ted  bonddistances was snal l .Sone crysta l lographic propert ies of  the members of  the ser iesw i th  n  - -  2  -  5  a re  desc r i bed  i n  chap te r  5 .  Each  o f  t hese  com-pounds  can  c rys ta l l i ze  i n  an  o r tho rhomb ic  and  i n  a  monoc l i n i cmodi f icat ion.  The or thorhombic nodi . f icat ion is  the most  s tableone at  and above room-temperature.  These or thorhombic modi f ica-t ions const i tu te a homologous ser ies as do the nronocl in ic  modi f l -cat ions of  the terns n = 3,  4 and 5.  The or ientat ions of  the mol-ecules in  the or thorhombic and ln the monocl in ic  crysta ls  appearf rom the st ructure analyses of  1,  10-d iphenyl -  1,  3,  5,  ?,9-decapen-taene  ( chap te r  6 ) .  These  o r i en ta t i ons  we re  found  by  b r i a l  anderror, naking use of the change of the lattice constants observedin  t h i s  se r i es  o f  compounds  and  o f  t he  op t i ca l  p rope r t i es .  The107co-ord lna, tes of  the carbn atoms were ref ined by Fbur ier  pro jec-tions. The available crystals iyere rather thin, however, and con-sequently the nunber of obseryod reflections was small. The expe-r i . nen ta l  bond  l eng tbs  we re  sub jec t  t o  a  s tanda rd  dev i . a t i on  o fapproxinate ly  0,03 & Therefore a deta i led compar ison of  observedwl th calculated bond lengths is  not  possib le.Thicker ,  wel l -developed or thorhombic crysta ls  of  1,8-d iphenyl -1,3,5,?-octatet raene were avai lable.  These crysta ls  were used foran X-ray structure determination described j.n chapter 7. In orderto  i nc rease  the  number  o f  obse rvab le  re f l ec t i ons  t he  c r ys ta l swere  coo led  down  to  -100oC by  means  o f  a  s t ream o f  evapo ra tedI i qu i . d  a i r .  A I I  h  &  I  r e f l ec t i ons  obse rved  w i th in  t he  reg ion  o fcopper radi .at ion were used for  tbe st ructure determinat ion.The  no lecu les  possess  a  cen t re  o f  symmet ry .  S ta r t j ' ng  f r om ase r i es  o f  app rox ima te  co -o rd ina tes ,  f ound  by  two -d j .mens iona lmethods,  the s igns of  the observed h k I  s t ructure factors werecalculated and used in a three-dimensional  Fbur ier  synthesis  oft he  e lec t ron  dens i t y  d i s t r i bu t i on  t h roughou t  t he  un i t  ce I I .  Thecarbon atoms of  the polyene chain are located in  a p lane,  as arethe atoms of  a pherv l  group.  These two p lanes make an angle of5,4"  wi th each other .  The hydrogen atoms are c lear ly  v j .s ib le inthe e l .ect ron densi ty  sect ions according to these p lanes.A f ina l  ref inement  of  the 'co-ord inates of  the carbon atoms wasobta ined by comput ing two d i f ferent ia l  syntheses;  in  one of  themthe observed and in the other  one the calculated st ructure fac-tors were used.  The standard deviat ion of  the exper imenta l  bondIengths arnounted to 0,004 E.There is  not  a c lose agreement  between calculated and observedbond  l eng ths  i n  d ipheny l -oc ta te t raene .  The  Ieng ths  o f  t he  C -Csingle bonds of  the polyene chain are s igni f icant l .y  snal ler  thanthe length of  a t rue s ingle bond,  but  the d i f ferences are not  aslarge as Dredicted theoret ica l ly .  The calculated increase of  the]engths of  the double bonds j .n  the chain wj . th  respect  to  a t ruedouble bond appears hard ly  or  not  at  a l l .  The C-C bonds of  the,po l yene  cha in  con ta in  ang les  o f  app rox ima te l y  124 " ,  bu t  two  o ft hese  ang les  a re  i nc reased  to  L27 " ,  p robabJ ,y  due  to  a  mu tua lrepul.sj-on of hydrogen atoms.l0B

Atoomafstanden in α,ω-Diphenyl-polyenen

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