Real-time imaging and spectroscopy during microwave assisted chemistry

Abstract

An instrument and associated method are disclosed for conducting microwave assisted chemical reactions. The instrument includes a microwave cavity, preferably a closed microwave cavity, for conducting microwave assisted chemical reactions, and a source for applying microwave radiation within the cavity and to a vessel and its contents. The instrument also includes an illumination source for illuminating the vessel and its contents, as well as means for visually observing the vessel and its contents, an infrared detector for monitoring the temperature of the vessel and its contents, and means for preventing the illumination source from saturating the infrared detector, thereby enabling concurrent visual observation and infrared monitoring.

1 . An instrument for conducting microwave assisted chemical reactions comprising:
 a microwave cavity;   a microwave-transparent vessel in said cavity;   a source for applying microwave radiation within said cavity and to said vessel and its contents;   an illumination source for illuminating said vessel and its contents in said cavity;   means for visually observing said vessel and its contents;   an infrared detector for monitoring the temperature of said vessel or its contents in said cavity; and   means for preventing said illumination source from saturating said infrared detector, thereby enabling concurrent visual observation and infrared monitoring.   
     
     
         2 . An instrument according to  claim 1  further comprising a waveguide in communication with said source and said cavity. 
     
     
         3 . An instrument according to  claim 1  wherein said illumination source comprises a visual illumination source. 
     
     
         4 . An instrument according to  claim 3  wherein said visual illumination source is selected from the group consisting of LEDs, fiber optic lights, fluorescent lights, incandescent lights, broad band light sources, and combinations thereof. 
     
     
         5 . An instrument according to  claim 1  wherein said means for preventing saturation of said infrared detector by said illumination source comprises a filter that prevents infrared wavelengths emitted by said illumination source from infiltrating said microwave cavity. 
     
     
         6 . An instrument according to  claim 1  wherein said visually observing means comprises a camera. 
     
     
         7 . An instrument according to  claim 1  wherein said visually observing means comprises a spectrophotometer that monitors chemical changes in the contents of said vessel. 
     
     
         8 . An instrument according to  claim 1  further comprising a processor in signal communication with said temperature detector, wherein said processor controls the microwave source in response to data received from said temperature detector. 
     
     
         9 . An instrument according to  claim 1  further comprising a processor in signal communication with said visual observation means, wherein said processor controls the microwave source in response to data received from said visual observation means. 
     
     
         10 . An instrument for conducting microwave assisted chemical reactions comprising:
 a microwave cavity;   a microwave-transparent vessel in said cavity;   a source for applying a continuous single mode of microwave radiation within said cavity and to said vessel and its contents;   an illumination source for illuminating said vessel and its contents in said cavity;   means for visually observing said vessel and its contents;   an infrared detector for monitoring the temperature of said vessel or its contents in said cavity; and   means for preventing said illumination source from saturating said infrared detector.   
     
     
         11 . An instrument according to  claim 10  wherein said illumination source comprises a visual illumination source. 
     
     
         12 . An instrument according to  claim 11  wherein said visual illumination source is selected from the group consisting of LEDs, fiber optic lights, fluorescent lights, incandescent lights, broad band light sources, and combinations thereof. 
     
     
         13 . An instrument according to  claim 10  wherein said means for preventing saturation of said infrared detector by said illumination source comprises a filter that prevents infrared wavelengths emitted by said illumination source from infiltrating said microwave cavity. 
     
     
         14 . An instrument according to  claim 10  wherein said means for preventing saturation of said infrared detector by said illumination source comprises means for allowing intermittent illumination of said vessel and its contents. 
     
     
         15 . An instrument according to  claim 14  wherein said means for allowing intermittent illumination of said vessel and its contents is selected form the group consisting of shutters, filter wheels, switches, and combinations thereof. 
     
     
         16 . An instrument according to  claim 10  further comprising a processor in signal communication with said temperature detector, wherein said processor controls the microwave source in response to data received from said temperature detector. 
     
     
         17 . An instrument according to  claim 10  further comprising a processor in signal communication with said visual observation means, wherein said processor controls the microwave source in response to data received from said visual observation means. 
     
     
         18 . An instrument for microwave assisted chemistry comprising:
 a source for applying microwave radiation to compositions in the instrument;   a detector capable of obtaining images of compositions in the instrument while microwaves are being applied from said source and of producing digital output that corresponds to the obtained images; and;   a processor in signal communication with said detector and said microwave source for moderating the application of microwaves from said source to the compositions in the instrument based upon the digital output from said detector.   
     
     
         19 . An instrument according to  claim 18  further comprising:
 means in signal communication with said processor for measuring the temperature of compositions in the instrument to which microwaves are applied from said source; and   means in signal communication with said processor for measuring the pressure generated by compositions in the instrument to which the microwaves are applied from said source;   wherein said processor moderates the application of microwaves from said source based upon the digital output from said detector and upon and at least one of the measured pressure and measured temperature.   
     
     
         20 . An instrument according to  claim 19  wherein said temperature measurement means is selected from the group consisting of thermometers, thermocouples, pyrometers and optical temperature detectors. 
     
     
         21 . An instrument according to  claim 19  wherein said pressure measurement means is selected from the group consisting of manometers, pressure gauges, and pressure transducers. 
     
     
         22 . An instrument according to  claim 18  wherein said detector includes an analog-digital converter for producing the digital output from the obtained images. 
     
     
         23 . An instrument according to  claim 18  wherein said processor moderates the application of microwaves independent of any visual display of obtained images. 
     
     
         24 . An instrument according to  claim 18  wherein said processor moderates the application of microwaves without any visual display of obtained images.