Highly fluorescent pyrrole-bf2 chromophores

Abstract

Fluorescent chromophores nicknamed BOPHY are provided. The chromophores may be readily synthesized in two steps from readily available reagents via the coupling of a pyrrole aldehyde or ketone with hydrazine, followed by reaction with BF 3 . The resultant symmetric and dimeric tetracycle is comprised of two BF 2 units in six-member chelate rings, appended by pyrrole units on the periphery. The quantum yield of fluorescence for the unmodified compound and the tetramethyl variant are near unity, with values 95 and 92% respectively in CH 2 Cl 2 .

What is claimed is: 
     
         1 . A compound defined by the following structure: 
       
         
           
           
               
               
           
         
       
       wherein each R is independently selected from chemical moieties that will form a covalent bond with one or more of the cyclic carbon atoms, and wherein two or more R groups may form a cyclic or heterocylic moiety. 
     
     
         2 . The compound of  claim 1 , wherein each R is independently selected from hydrogen, hydroxyl, branched or unbranched, saturated or unsaturated monovalent organic groups, nitrogen-containing moieties, halogen, halogenated moieties, oxygen-containing moieties, phosphorus-containing moieties, silicon-containing moieties, and sulfur-containing moieties, or two or more R groups may together form an optionally substituted cyclic or heterocyclic moiety. 
     
     
         3 . The compound of  claim 1 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7  and R 8  are independently selected from hydrogen, hydroxyl, halogen, alkyl, carboxyalkyl, aryl, sulfo, isocyano, isothiocyano, and formyl, alone or in combination. 
     
     
         4 . The compound of  claim 1 , wherein R 1  is selected from hydrogen, an alkyl group, and a cyano group, or R 1  and R 2  taken together with any intervening atoms comprise a group chosen from an optionally substituted monocyclic group and an optionally substituted C 6-24  multicyclic group. 
     
     
         5 . The compound of  claim 1 , wherein R 2  is selected from hydrogen, an alkyl group, and a cyano group, or R 2  and R 1  taken together with any intervening atoms comprise a group chosen from an optionally substituted monocyclic group and an optionally substituted C 6-24  multicyclic group, or R 2  and R 3  taken together with any intervening atoms comprise a group chosen from an optionally substituted monocyclic group and an optionally substituted C 6-24  multicyclic group. 
     
     
         6 . The compound of  claim 1 , wherein R 3  is selected from hydrogen, an alkyl group, and a cyano group, or R 3  and R 2  taken together with any intervening atoms comprise a group chosen from an optionally substituted monocyclic group and an optionally substituted C 6-24  multicyclic group. 
     
     
         7 . The compound of  claim 1 , wherein R 4  and R 8  are independently selected from hydrogen, an optionally substituted monocyclic group, an optionally substituted C 6-24  multicyclic group, and an optionally substituted chromophoric group. 
     
     
         8 . The compound of  claim 1 , wherein R 5  is selected from hydrogen, an alkyl group, and a cyano group, or R 5  and R 6  taken together with any intervening atoms comprise a group chosen from an optionally substituted monocyclic group and an optionally substituted C 6-24  multicyclic group. 
     
     
         9 . The compound of  claim 1 , wherein R 6  is selected from hydrogen, an alkyl group, and a cyano group, or R 6  and R 5  taken together with any intervening atoms comprise a group chosen from an optionally substituted monocyclic group and an optionally substituted C 6-24  multicyclic group, or R 6  and R 7  taken together with any intervening atoms comprise a group chosen from an optionally substituted monocyclic group and an optionally substituted C 6-24  multicyclic group. 
     
     
         10 . The compound of  claim 1 , wherein R 7  is chosen from hydrogen, an alkyl group, and a cyano group, or R 7  and R 6  taken together with any intervening atoms comprise a group chosen from an optionally substituted monocyclic group and an optionally substituted C6- 24  multicyclic group, or R 8  and R 7  taken together with any intervening atoms comprise a group chosen from an optionally substituted monocyclic group and an optionally substituted C 6-24  multicyclic group. 
     
     
         11 . The compound of  claim 1 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8  are independently selected from of C 1 -C 30  alkyl, C 1 -C 30  alkenyl, C 1 -C 30  alkynyl, C 1 -C 30  aryl, C 1 -C 30  alkoxy, C 1 -C 30  phenoxy, C 1 -C 30  thioalkyl, C 1 -C 30  thioaryl, C 1 -C 30  C(O)OR 9 , N(R 10 )(R 11 ), C(O)N(R 9 )(R 10 ) F, Cl, Br, NO 2 , CN, acyl, carboxylate, and hydroxyl, wherein R 9 , R 10  and R 11  are independently selected from the group of hydrogen, C 1 -C 30  alkyl, and C 1 -C 30  aryl. 
     
     
         12 . The compound of  claim 1 , wherein one or more R groups are independently selected from hydrogen, halogen, hydroxide, and hydrocarbyl groups. 
     
     
         13 . The compound of  claim 12 , wherein said hydrocarbyl groups contain from 1 to 30 carbon atoms and are independently selected from alkyl, cycloalkyl, substituted alkyl, substituted cycloalkyl, alkenyl, cycloalkenyl, substituted alkenyl, substituted cycloalkenyl, aryl, substituted aryl, allyl, aralkyl, alkaryl, alkynyl, cyano, isocyano, isothiocyano, oxo-hydrocarbyl, sulfo-hydrocarbyl, and aza-hydrocarbyl groups. 
     
     
         14 . The compound of  claim 1 , wherein each R is independently selected from hydrogen and methyl. 
     
     
         15 . A method for synthesizing a dinuclear boron heterocyclic chromophore, the method comprising the steps of:
 combining a bis(pyrrole imine) hydrazine with boron trifluoride.   
     
     
         16 . A method for synthesizing a dinuclear boron heterocyclic chromophore, the method comprising the steps of:
 combining a pyrrole aldehyde or ketone, or a mixture of two or more compounds selected from pyrrole aldehydes and ketones, with a hydrazine to form a bis(pyrrole imine) hydrazine; and   combining the bis(pyrrole imine) hydrazine with boron trifluoride to form a dinuclear boron heterocyclic chromophore.   
     
     
         17 . The method of  claim 16 , wherein the pyrrole aldehyde or ketone is represented by the structure: 
       
         
           
           
               
               
           
         
       
       wherein each R is independently selected from hydrogen, hydroxyl, branched or unbranched, saturated or unsaturated monovalent organic groups, nitrogen-containing moieties, halogen, halogenated moieties, oxygen-containing moieties, phosphorus-containing moieties, silicon-containing moieties, and sulfur-containing moieties, or two or more R groups may together form an optionally substituted cyclic or heterocyclic moiety, with the proviso that the substituent does not interfere with the formation of the 6-member chelate rings of the BOPHY structure. 
     
     
         18 . The method of  claim 16 , wherein the bis(pyrrole imine) hydrazine is selected from compounds having the structure: 
       
         
           
           
               
               
           
         
       
       wherein each R is independently as described in any of the preceding claims. 
     
     
         19 . The method of  claim 18 , wherein each R is independently selected from hydrogen, hydroxyl, branched or unbranched, saturated or unsaturated monovalent organic groups, nitrogen-containing moieties, halogen, halogenated moieties, oxygen-containing moieties, phosphorus-containing moieties, silicon-containing moieties, and sulfur-containing moieties, or two or more R groups may together form an optionally substituted cyclic or heterocyclic moiety, with the proviso that the substituent does not interfere with the formation of the 6-member chelate rings of the BOPHY structure. 
     
     
         20 . The method of  claim 16 , wherein the dinuclear boron heterocyclic chromophore is defined by the following structure: 
       
         
           
           
               
               
           
         
       
       wherein each R is independently selected from chemical moieties that will form a covalent bond with one or more of the cyclic carbon atoms, and wherein two or more R groups may form a cyclic or heterocylic moiety. 
     
     
         21 .- 31 . (canceled)