Two Types Of Novel Structures Synthesis And Properties Of Organic Boron Difluoride Complexes

Recently, there have been great attentions on BF2 complex since they have excellent characters and lots of applications on chemistry and biology. There are so many papers on N,N double-dentate and O,O double-dentate, and only a few papers about N,O double-dentate. In past, we design and synthesis two BF2 complexes which was 3-(2-Oxo-2-phenyl-ethylidene)-3,4-dihydro-1H-quinoxalin-2-one and 3-(2-Oxo- 2-phenyl-ethylidene)-3,4-dihydro-benzo[1,4]oxazin-2-one, and then we test their fluorescent character. Their structures are novel and show bright yellowish green fluorescence in solution. Basing on this work, We want to do some new research on N,O double-dentate, the major research includes the following:1. A series of 5-Methyl-2-phenyl-4-(phenyl-phenylimino-methyl)-2H-pyrazol- 3-ol-BF2 complexes is prepared from 5-Methyl-2-phenyl-1,2-dihydro-pyrazol-3-one. We test their characters with IR,UV,¹H NMR,¹³C NMR,electrochemistry: these complexes are steady in high temperature and have large molar extinction coefficient, and blue shift in UV spectrum happens after chelation with no fluorescence. With knowledge and the results of theoretic calculation, we think the major reason is that the hexahydric ring has broken the complex's complanate. The key reason is that the N atom'sσbond is a random rotational bond.2. A series of 2-Quinolin-2-yl-phenol-BF2 complexes are synthesized from diffe- rent processes and are test in IR,UV,1H NMR,13C NMR,X-ray,electrochemistry:these complexes have high melting point and large molar extinction coefficient and a red shift happens after chelation. These complexes have strong fluorescent both in solution and in solid state with large Stocke's shift.With knowledge and the results of theoretic calculation, we think the major reason is that the hexahydric ring has improved the complex's complanate and increase the conjugated area. The key reason is that the N atom'sσbond is a unrotational bond.Therefore, we think that the N atom's unrotationalσbond is a necessary reason for complex with strong fluorescent. This will be suggestion for our next research in molecular structure's design in the future.