Research On The Molecular Geometry, Reactive Area And Ultraviolet Spectrum Of Azapyridine Compounds

Density functional theory(DFT)methods,B3LYP as well as 6-31G*basis sets were employed to study the characters of triazacorone and its derivatives.All results are divided into five parts and elaborated as below:A review on research advances and applications of organic photoelectronic materials is elaborated in Chapter 1,where I analyzed the situation and put forward the thesis topics;To pick out appropriate and reasonable methods,a review on theoretical and computational methods is provided in Chapter 2,accordingly,the methods and research scheme are chosen for triazacorone and its derivatives.The geometrical characters,molecular orbital features,electrostatics potentials,charge distributions,NICS,following with UV spectroscopy,electronic and optical properties are studied with theoretical methods for triazacorone and derivatives(Chapter 3),coronaquinone and its derivates(in Chapter 4)and ?-extended tripyridine and its derivatives.We found that:1.Trazacorone and its derivatesWe have analyzed the geometry reasonality with geometrical optimizations and frontier molecular orbitals analysis.The computional results indicate that the three different types of clcylo rings have different electrostatic potential(ESP),and show a sequence of C>A>B,on the triazacorone and their derivates.In a common sence,the stronger the electrowithdrawing substituted group is,the lower the ESP value is.Thus strong electrowithdrawing group affected the ESP severely.Comparing the charge distribution on the triazacorone,we can learn that ADCH charge distribution is more reasonable than NPA charge and Mulliken charge distributions.From the ADCH charge distribution,we can successfully predict the activity point on the triazacorone and their derivates.We have compared the NCIS(0)value on the ring A,B,C,seperately for all five triazacorone and its derivates.It is found that the value of NICS(0)are in a sequence of B<A<C.The lowest NICS(0)point is around 0.8 A from the centre of ring A,and B except in compound 2.The lowest NICS(0)point is far from the centre of ring C,which is around 1.6 A in compound 1 and 3,while for compound 2,4 and 5,it is 1.4 AThe electronic optical adsoption bands are red-shifted from 2 to 5,which are 262.4 nm?312.9 nm,345.5 nm,367.8 nm and 385.6 nm for 2,1,3,4 and 5,respectively.2.Triazacoronaquinone and its derivatesThe computational results indicate that the substitued group brings less variation to triazacoronaquinone comparing to the triazaconrone in geometry.The HOMO and LUMO orbitals are influenced severely by the carbonyl group,while the substituted groups have less effect on it.All energy gaps between HOMO and LUMO are no more that 3.0 eV,the gaps for the five triazacoronaquinone and its derivates are in a sequence of 3<5<4<11<2Results indicate that different substituted group has different effect on the electrostatic potential.The electrostatic potential of the five compounds are in a range of 31.99-45.52 kcal/mol,-34.57-40.27 kcal/mol,-39.43-34.51 kcal/mol,-27.91-60.21 kcal/mol,-33.57-42.86 kcal/mol for compound 1 to 5,respectively.For a same compound,the ESP of three rings are ranked in 4>1>2>5>3The aromaticity of ring A is stronger than ring B and C,and the NICS(0)values are in a sequence of A<C<B.The point of maximum NICS vale of ring A is 0.8 A far from the cetre of ring A,while it is 1.0 A far from the cetre of ring CThe calculated adsorption peak of compound 1,2,3,4 and 5 are 345.4 nm,360.1 nm,378.4 nm,345.9 nm and 385.6 nm,respectively.Whether the sustituted group is electrowithdrawing or electrodonating,the adsorption band peaks are red-shifted.The stronger the electrowithdrawing group is,the stronger the red-shift band peak observed3.?-extended tripyridines and the derivatesThe pyridyl groups are mantained in planar after introducing-Cl and-C4H7The energy gap of HOMO and LUMO are predicted to be 3.79,3.38 and 3.81 for compounds 1,2 and 3,respectivelyComputational results indicated that the electrostatic ranges are-74.20-20.20 kcal/mol,-70.75-26.85 kcal/mol,-74.20-20.37 kcal/mol for compounds 1,2 and 3,respectively.Substituted group enhances the electronic desity,thus,the electrostatic maximum decreases,and the surface of the negative electrostatic potential increases The ESP peak of the six rings in compound 1 are in sequence of 2>5>4>1>6>3 Which for compound 3,it is 2>5>4>1>6>3.We can also predict the reactvity point in the compounds with electrostatic potatial surface.Cl4,Cl8,Cl9,C23 and C24 has more negative charges compare to Cl4,Cl9 and C24.Thus the formers are easily to be attacked by electrophile reagents.The reactivity point can be predicted with CFF value.The computional results indicate that the larger the f value is,the stronger the reactivity is.The most easily to be attacked atom is C23 with electrophile reagent.The aromaticity prediction with NICS(0.8)is in a sequence of 3>1>2.For copound 1 and 2,the NICS(0.8)on different rings are in a sequence of 4<3<1<6<5<2.While for compound 3,the sequence is3<4<1<6<2<5.The chemical active ring is ring ?,the electronic optical adsoption peaks are 336.3 nm,351.4 nm,and 342.3 nm for the three studied compounds 1,2,and 3,respectively.These results are quite in consistent with the experimental results.A summary of the performance in this thesis is finally elaborated in Chapter 6.We expected the thesis can help us to deeply understand the experimental results,and provide a quite reasonable prediction of new compounds with expected properties.