Process of quadricyclane production

Abstract

The present invention relates to a process for efficiently producing quadricyclane by the conversion of norbornadiene. A sensitizer, such as a substituted diaminobenzophenone having a solubility in norbornadiene greater than that of Michler's Ketone, may be added to the norbornadiene to form a solution, wherein the sensitizer decreases the induction period at the beginning of the reaction, increases the photon or quantum efficiency of conversion of norbornadiene to quadricyclane, and increases the rate of conversion at the end of the reaction. If the solution is irradiated with light from a metal halide-doped mercury arc lamp to photochemically transform the norbornadiene to quadricyclane, the conversion is more efficient than when other light sources are utilized. Furthermore, the addition of triethylamine to the solution tends to result in the formation of fewer by-products in the transformation reaction.

We claim:  
     
         1 . A process for the production of quadricyclane, comprising the steps of: 
 providing norbornadiene;    adding a substituted diaminobenzophenone to said norbornadiene to form a solution, said substituted diaminobenzophenone having a solubility in norbornadiene greater than the solubility of Michler's Ketone in norbornadiene; and    irradiating said solution with light, whereby said norbornadiene is converted to quadricyclane.    
     
     
         2 . The process of  claim 1  wherein said norbornadiene is purified.  
     
     
         3 . The process of  claim 1  wherein said substituted diaminobenzophenone is Ethyl Michler's Ketone.  
     
     
         4 . The process of  claim 3  wherein said Ethyl Michler's Ketone is added to said norbornadiene in the range of about 0.2% to about 3.86% by weight.  
     
     
         5 . The process of  claim 1  wherein said irradiating step is carried out with a metal halide-doped mercury arc lamp.  
     
     
         6 . The process of  claim 5  wherein said irradiating step is carried out with an iron halide-doped mercury arc lamp.  
     
     
         7 . The process of  claim 1  further comprising the step of adding a base to said solution to reduce the formation of by-products during said conversion.  
     
     
         8 . The process of  claim 7  wherein said base is triethylamine.  
     
     
         9 . The process of  claim 1  wherein said solution is irradiated with a lamp having enhanced output in the wavelength range of about 250 nm to about 400 nm.  
     
     
         10 . The process of  claim 9  wherein said solution is irradiated with a lamp having enhanced output in the wavelength range of 340 nm to 390 nm.  
     
     
         11 . The process of  claim 1 , comprising the step of regulating the temperature of said solution between about −40° C. and about 60° C.  
     
     
         12 . The process of  claim 11 , where said temperature is regulated between about −10° C. and about 30° C.  
     
     
         13 . The process of  claim 12 , wherein said temperature is regulated at about 0° C.  
     
     
         14 . The process of  claim 1  wherein said irradiating said solution with light comprises passing the light through a filter to remove wavelengths shorter than about 300 nm.  
     
     
         15 . The process of  claim 14  wherein said filter is a borosilicate glass filter having a thickness in the range from about 0.5 mm to about 10 mm.  
     
     
         16 . Quadricyclane formed by the process of  claim 1 .  
     
     
         17 . A process for the production of quadricyclane, comprising the steps of: 
 providing norbornadiene; and    irradiating said norbornadiene with light emitted from an iron halide-doped mercury arc lamp, whereby said norbornadiene is converted to quadricyclane.    
     
     
         18 . The process of  claim 17  wherein said norbornadiene is purified.  
     
     
         19 . The process of  claim 17  further comprising the step of adding a substituted diaminobenzophenone to said norbornadiene to form a solution, wherein said substituted diaminobenzophenone has solubility in norbornadiene greater than Michler's Ketone.  
     
     
         20 . The process of  claim 19  wherein said substituted diaminobenzophenone is Ethyl Michler's Ketone.  
     
     
         21 . The process of  claim 20  wherein said Ethyl Michler's Ketone is added to said norbornadiene in the range of about 0.2% to about 3.86% by weight.  
     
     
         22 . The process of  claim 17  further comprising the step of adding a base to said solution to reduce the formation of by-products during the conversion.  
     
     
         23 . The process of  claim 22  wherein said base is triethylamine.  
     
     
         24 . The process of  claim 17 , comprising the step of regulating the temperature of said norbornadiene between about −40° C. and about 60° C.  
     
     
         25 . The process of  claim 24 , where said temperature is regulated between about −10° C. and about 30° C.  
     
     
         26 . The process of  claim 25 , wherein said temperature is regulated at about 0° C.  
     
     
         27 . The process of  claim 17  wherein said irradiating step comprises passing the light through a filter to remove wavelengths shorter than about 300 nm.  
     
     
         28 . The process of  claim 27  wherein said filter is a borosilicate glass filter having a thickness in the range from about 0.5 mm to about 10 mm.  
     
     
         29 . Quadricyclane formed by the process of  claim 17 .  
     
     
         30 . A process for producing quadricyclane, comprising the steps of: 
 providing norbornadiene;    adding triethylamine to said norbornadiene to form a solution; and    irradiating said solution with light, whereby said norbornadiene is converted to quadricyclane and said triethylamine reduces the formation of by-products during the conversion.    
     
     
         31 . The process of  claim 30  wherein said norbornadiene is purified.  
     
     
         32 . The process of  claim 30  further comprising the step of adding a substituted diaminobenzophenone to said norbornadiene.  
     
     
         33 . The process of  claim 30  wherein said substituted diaminobenzophenone is Ethyl Michler's Ketone.  
     
     
         34 . The process of  claim 30  wherein said Ethyl Michler's Ketone is added to said norbornadiene in the range of about 0.2% to about 3.86% by weight.  
     
     
         35 . The process of  claim 30  wherein said irradiating step is carried out with an iron halide-doped mercury arc lamp.  
     
     
         36 . The process of  claim 30 , comprising the step of regulating the temperature of said solution between about −40° C. and about 60° C.  
     
     
         37 . The process of  claim 36 , where said temperature is regulated between about −10° C. and about 30° C.  
     
     
         38 . The process of  claim 37 , wherein said temperature is regulated at about 0° C.  
     
     
         39 . Quadricyclane formed by the process of  claim 30 .  
     
     
         40 . A process for the production of quadricyclane, comprising the steps of: 
 providing norbornadiene;    adding a substituted diaminobenzophenone to said norbornadiene to form a solution; and    irradiating said solution with a metal halide-doped mercury arc lamp, whereby said norbornadiene is converted to quadricyclane.    
     
     
         41 . The process of  claim 40  wherein said irradiating step is carried out with an iron halide-doped mercury arc lamp.  
     
     
         42 . The process of  claim 40  wherein said solution is irradiated with a lamp having enhanced output in the wavelength range of about 250 nm to about 400 nm.  
     
     
         43 . The process of  claim 42  wherein said solution is irradiated with a lamp having enhanced output in the wavelength range of 340 nm to 390 nm.  
     
     
         44 . The process of  claim 40  wherein said substituted diaminobenzophenone is Ethyl Michler's Ketone.  
     
     
         45 . The process of  claim 40  wherein said Ethyl Michler's Ketone is added to said norbornadiene in the range of about 0.2% to about 3.86% by weight.  
     
     
         46 . The process of  claim 40  wherein said norbornadiene is purified.  
     
     
         47 . The process of  claim 40  further comprising the step of adding triethylamine to said solution to reduce the formation of by-products during the conversion.  
     
     
         48 . The process of  claim 40 , comprising the step of regulating the temperature of said solution between about −40° C. and about 60° C.  
     
     
         49 . The process of  claim 48 , where said temperature is regulated between about −10° C. and about 30° C.  
     
     
         50 . The process of  claim 49 , wherein said temperature is regulated at about 0° C.  
     
     
         51 . Quadricyclane formed by the process of to  claim 40 .  
     
     
         52 . A process for the production of quadricyclane, comprising the steps of: 
 providing purified norbornadiene;    adding Ethyl Michler's Ketone to said norbornadiene in the range of about 0.2% to about 3.86% by weight to form a solution; and    irradiating said solution with an iron halide-doped mercury arc lamp having an enhanced output in the range of about 340 nm to about 390 nm, wherein said norbornadiene is converted to quadricyclane.    
     
     
         53 . The process according to  claim 52  further comprising the step of adding triethylamine to said solution to reduce the formation of by-products during the conversion.  
     
     
         54 . The process according to  claim 52  further comprising the step of regulating the temperature of said solution at about 0° C.  
     
     
         55 . Quadricyclane formed by the process of  claim 52 .  
     
     
         56 . A process for the production of quadricyclane, comprising the steps of: 
 providing purified norbornadiene;    adding Ethyl Michler's Ketone to said norbornadiene in the range of about 0.2% to about 3.86% by weight to form a solution;    adding triethylamine to said solution;    irradiating said solution with an iron halide-doped mercury arc lamp having an enhanced output in the wavelength range of about 340 nm to about 390 nm, wherein said norbornadiene is converted to quadricyclane and said triethylamine reduces the formation of by-products during the conversion; and    regulating the temperature of said solution at about 0° C.    
     
     
         57 . Quadricyclane formed by the process of  claim 56 .  
     
     
         58 . A product formed by the process of driving a non-polymerization solution-phase photochemical transformation, comprising the steps of: 
 providing an organic solution having the potential for a non-polymerization solution-phase photochemical transformation; and    irradiating said solution with a metal-halide doped mercury arc lamp to drive a non-polymerization solution-phase photochemical transformation within said solution.    
     
     
         59 . A product formed by the process of driving a non-polymerization solution phase photochemical transformation, comprising the steps of: 
 providing an organic solution having the potential for a non-polymerization solution-phase photochemical transformation;    adding a base to said solution; and    irradiating said solution with light, whereby said base reduces the formation of by-products during said non-polymerization solution phase photochemical transformation.