ION-SENSITIVE COMPOUNDS

Abstract: Ion-sensitive compounds are provided comprising a quaternary polypyridinium receptor designed to bind anionic species by the formation of a receptor-substrate complex. The receptor comprises one or more quaternary 2,2'-bipyridyl moieties and is represented by the formula R<1>-Y-R<2> wherein Y is represented by structure (I) in which R<1>, R<2>, R<3>, R<4> and q have meanings as given in the description. The compounds are of use in applications requiring anion detection or removal.

Description: Ion-sensitive Compounds The invention relates to ion-sensitive compounds. More particularly, the invention relates to ion-sensitive compounds comprising a quaternary polypyridinium receptor designed to bind anionic species by the formation of a receptor-substrate complex. Anion receptors comprising a plurality of quaternary amine groups are known. Examples of such compounds may be seen in P.G. Potvin and J-M Lehn, Prog. Macrocyclic Chem . , 1981 , 3, 214. L.A. Summers, "The Bipyridinium Herbicides", Academic Press, New York, 1980, describes the use of certain compounds comprising diquaternary 2,2'- bipyridinium moieties in herbicidal applications. There is a continuing need to provide new receptor compounds for a variety of applications. For example, such compounds may be incorporated in electrochemical sensors for anion determination. A number of electrochemical sensors utilising ion receptors are known. Alternatively, such compounds may be used in removal devices where levels of a given anion need to be kept low. A number of removal devices utilising ion receptors are known. It is also desirable to provide receptor compounds which can be readily synthesised. The invention provides a new class of anion receptors. The ion-sensitive compounds of the invention have the formula A n+ B n~ wherein A represents a cation capable of forming a receptor-substrate complex with an anion, B represents one or more counter anions and n is an integer from 3 to 10, characterised in that the cation is an anion receptor represented by the formula R-^-Y-R 2 wherein Y ' is represented by the structure each q independently is an integer from 1 to 6/ R3 and R 4 are each independently H or a lower alkyl group having from 1 to 4 carbon atoms, or R3 and R 4 taken together represent an ethylene bridging group; R**** and R 2 are each independently selected from organic cations and non-ionic organic groups wherein at least one of R-- and R 2 is an organic cation and the combined ionic charge of R 1 and R 2 is from 1 to 8; or, R 1 is H and R 2 is -X-Y-H wherein X is a linking group and Y is as defined above; or, R-- and R 2 taken together represent -X-Y-X- wherein X and Y are as defined above. Preferred compounds having the formula defined above include compounds wherein q is 1. R * ** ** and R 4 may each be methyl. Examples of non-ionic groups from which R 1 and R 2 may be chosen include alkylamino, poly(alkyla ino) , aryla ino, poly(arylamino) , alkylamido, arylamido, alkylphosphoramido, arylphosphoramido, alkylsulphonamido, arylsulphonamido, alkyloxycarbonyl, aryloxycarbonyl, pyridyl and bipyridyl. "Examples of organic cations from which R***- and R 2 may be chosen include the quaternised forms of the non-ionic groups listed above. Particular examples are 2,2*-bipyridinium, r 4'-bipyridinium and ~[ + N(R5)2 _ R^]p- ^ wherein each R^ independently is hydrogen or an alkyl group of from 1 to 4 carbon atoms; R> is an alkylene group of from 1 to 3 carbon atoms; R 7 is hydrogen or -N(R 5 )3 and p is an integer from 1 to 4. Preferred compounds include those wherein both R- * - and R 2 are organic cations. Examples of suitable linking groups represented by X include alkylene, arylene, and quaternised or unquaternised amine- or polyamine-containing groups such as alkylamino, arylamino, aminoalkyleneamino, amino[poly(alkyleneamino) ] , bipyridyl and bipyridylamino. Preferred groups include 4,4'- bipyridinium and -[ + N . (R 5 )2 _ R^]p-N + (R 5 ) 2~ wherein R 5 , R6 and p are as defined above. In the definitions given above, all alkyl, alkylene, aryl and arylene groups, when present as such or as part of another substituent, are optionally substituted. Specific examples of preferred compounds of the invention are as follows. ( 1 ) ( 2 ) ( 3 ) The compounds of the invention can be prepared using S^'-dibromoalkyl^^'-bipyridyl or 5- bromoalkyl-5'-alkyl-2,2'-bipyridyl as the starting materials. Reaction of the dibromo substituted material with an appropriate amine e.g. 4, 4 '-bipyridyl followed by quaternisation with an alkylating agent e.g. methyl iodide will produce the 5,5'-disubstituted compounds of the invention in which the 2,2'- bipyridinium moiety is flanked by positively charged groups. Alternatively, the dibromo compound can be reacted with a variey of compounds which have been deprotonated to give a ono-anion e.g. the mono anion produced by deprotonating 2,2'-bipyridyl with butyl lithium. Reaction of the monobromo substituted material with an appropriate diamine e.g. N,N*-dimethyl ethylenedia ine followed by quaternisation with an alkylating agent will produce compounds of the invention in which two 2,2'-bipyridinium moieties are attached through a linking group. Other bifunctional linking groups may be reacted with the monobromo substituted material in this way with or without formation of a di-anion by deprotonation. Specific examples of the preparation of compounds of the invention are given as follows. Example 1 N,N'-Bis(5'-methyl-2,2 » -bipyridyl-5-methylene)-N,N'- dimethyl-ethylene-diamine N,N'-Dimethyl ethylene diamine (76mg. 0.86mmol) was dissolved in acetonitrile (30cm*^) , potassium carbonate (2.64g, 19.1mmol) added and the mixture heated to reflux under nitrogen. To this was added dropwise a solution of 5-bromomethyl-5'-methyl-2,2'-bipyridyl (0.50g, 1.90mmol) in acetonitrile (30cm 3 ) with stirring and the resultant mixture heated at reflux for 3h. After this time the mixture was cooled to room temperature, the solid removed by filtration and the solvent removed from the filtrate under reduced pressure to give a deep orange residue. This was then chromatographed on alumina using dichloromethane/methanol (99.1) as elutant. A pale orange band was collected. After removal of the solvent the product was recrystallised from acetonitrile to give small off-white crystals of the required ligand (0.17g, 43%) m.p. 160-161°C. M.S. (FAB) [m/z+H] + 453, tCH 2 bipyCH 2 N(Me)CH 2 ] + 226, [CH 2 bipyCH 2 J + 183. I.R. 3000cm -1 (aromatic CH stretch), 2850/2800cm _1 (aliphatic CH stretch) , 1600/1580cm -1 (C=C/C=N ring stretch) --H NMR (CDCI3, 270MHz) δ: 2.24 (6H, s, bipyCH 2 N£H 3 ) , 2.39 (6H, s, bipy£H 3 )., 2.59 (4H, s, bipyCH NCϋ 2 ) , 3.58 (4H, s, bipy£H 2 ), 7.61 (2H, d, 3 J=8.lHz, bipyH 4 ■) , 7.77 (2H, d, 3 J=8.2Hz, bipyH 4 ) , 8.26 (2H, d, 3 J=8.2Hz, bipyH 3 ) , 8.30 (2H, d, 3 J=8.1Hz,bipyH3t) , 8.49 (2H, s, bipyH 6 «), 8.56 (2H, s, bipyH 6 ) 13 C NMR (CDCI3, 67. 8MHz) δ : 18 .35 (bipy£H 3 ) . 42 .55 (bipyCH 2 N£H 3 ) , 55 .11 and 59 .76 (bipy £H 2 N£H 2 ) , 120 .41, 120 .50, 133.22, 134 .12 , 137 .43, 137 .57 , 149 .59, 149.70, 153.59 and 155.25 (aromatic C) Analysis calculated for C 2 gH3 2 Ng; C:74.3%, H:7.1%, N:18.6%. Found C:74.5%, H:6.8%, N:18.9%. N,N'-Bis(N,K r ,5'-trimβthyl-2,2'-bipyridyl-5- methylene)-N, ,N',N'-tβtramethyl-ethylene-diammonium hexa(hexafluorophosphate) (1) The ligand (70mg, 0.16mmol) was dissolved in dimethyl sulphate (10cm 3 ) with stirring and heated to 75°C under nitrogen for 7 days. The solution was cooled to room temperature and the precipitate collected for filtration. The solid was washed with acetone (3 x 10cm 3 ) and then dissolved in water (15cm 3 ) . To this solution was added a saturated aqueous solution of ammonium hexafluorophosphate until precipitation ceased to occur. The precipitate was collected by filtration, washed with water (2 x 10cm 3 ) and dried under vacuum over silica gel to give a white solid (73mg) . The solid was dissolved in acetonitrile under nitrogen with stirring. To this was added methyl iodide and the resultant solution heated at reflux for 18 days. After this time the mixture was cooled to room temperature. A solution of tetra-butyl ammonium chloride (0.2g in 5cm 3 of acetonitrile) was added to precipitate the product as the chloride salt. This was collected by filtration, dried, then dissolved in water (10cm 3 ) . To the solution was added a saturated aqueous solution of ammonium hexafluorophosphate until precipitation ceased to occur. The solid was collected by filtration, washed with water (2 x 5cm 3 ) and dried under vacuum over silica to give the hexa- cationic receptor (1) (24mg, 11%) m.p. 195°C (decomp) . M.S. (FAB) [m/z-PF 6 -] + 1267, [m/z-2PF 6 -] + 1122, [m/z- CH 3 + -2PF 6 -] + 1107, [m/z-CH 3 + -3PFg-]+ 962, [m/z-4CH 3 +- 5PF 6 -] + 629 • J-H NMR (DMSO, 400MHz) δ: 2.68 (6H, S, bipy£U3) , 3.21 and 3.24 (12H, 2s, bipyCH 2 N + ( U3) 2 , 4.14 and 4.24 (12H, 2s, bipyN + -£H 3 ) , 4.27 (4H, s, bipyCH 2 N + £H 2 ) 5.02 (4H, s, bipy£Ii 2 ), 8.19 (2H, d, 3 J=8.1Hz, bipyH 4 1 ) , 8.63 (2H, d, 3 J=8.1Hz, bipyH 4 ) , 8.79 (2H, d, 3 J=8.1Hz), bipyH 3 ι), 9.07 (2H, d, 3 J=8.1Hz, biρyH 3 ) , 9.42 (2H, s, bipyH 6 «), 9.53 (2H, s, bipyH 6 ) 13 C NMR (DMSO, δ: 18.12 (bipy£H 3 ) , 47.42 and 48.11 (bipyN + -£H 3 ) , 49.58 and 49.74 (bipyCH 2 N + (£H 3 ) 2 ) , 57.93 (bipyCH 2 N + £H 2 ) , 62.60 (bipyCH 2 ) , 129.47, 129.70, 131.22, 139.78, 141.63, 144.67, 146.72, 149.14, 151.00 and 152.09 (aromatic C) . Analysis calculated for C3 H5oF3gNgPg; C:28.9%, H:3.6%, N:6.0%. Found C:29.4%, H:3.6%, N:6.1% Analysis calculated for C3 H5oF36NgP6' C:28.9%, H:3._%, N:6.0%. Found C:29.4%, H:3.6%, N:6.1% Anion Binding The receptor (1) displayed substantial shifts of the signals of the ^H NMR spectrum following the addition of one equivalent of tetrabutyl ammonium chloride. Analysis of the signals confirmed the formation of a complex between the receptor and the chloride ion. Example 2 5,5'-Bis(4,4'-bipyridyl-N-methylβne)-2,2'-bipyridyl bis(hexafluorophosphate) ,4'-Bipyridyl (18.2g, 116.5mmol) was dissolved in acetonitrile (700cm 3 ) with stirring under nitrogen and heated to reflux. A solution of 5, 5'- bis(bromomethyl)-2,2-bipyridyl (0.80g, 2.34mmol) in acetonitrile (300cm 3 ) was added dropwise and the resultant solution heated at reflux for 48h. The mixture was then cooled to room temperature and the volume of the solvent reduced to 400cm 3 . The solid was collected by filtration, washed with acetonitrile (3 x 50cm 3 ) and dried under vacuum. The solid was then dissolved in water (250cm 3 ) with stirring and a saturated aqueous solution of ammonium hexafluorophophate added until no further precipitation occurred. The mixture was stirred for Ih to ensure complete precipitation of the product. This was then collected by filtration, washed with water (3 x 20cm 3 ) and dried under vacuum over silica gel to produce a white solid (1.61g, 88%), m.p.>300°C. M.S. (FAB) [m/z-PF 6 -] + 639.5, [m/z-2PF 6 -] + 493.5, [m/z- 4.4'-bipyridyl-2PF 6 -] + 338.4, iH NMR (DMSO, 270MHz) δ: 6.01 (4H, s, bipy£H 2 ) , 8.04 (4H, d, 3 J=5.9Hz, 4,4 I H 3 «), 8.16 (2H, d, 3 J=8.4Hz, bipyH 4 ), 8.46 (2H, d, 3 J=8.4Hz, bipyH 3 ) , 8.68 (4H, d, 3 J=6.7Hz, 4,4'H 3 ), 8.89 (4H, d, 3 J=5.9Hz, 4,4'H 2 , 8.97 (2H, s, bipyHg), 9.42 (4H, d, 3 J=6.7Hz, 4,4'H 2 ) 13 C NMR (DMSO, 67.8MHz) δ: 60.25 (bipy£H) , 120.79, 121.91, 125.88, 130.67, 137.93, 140.80, 145.46, 149.78, 150.86, 152.91 and 155.19 (aromatic C) Analysis calculated for C3 2 N gF 12 NgP 2 ;C:49.0%, H:3.3%, N:10.7%. Found C:48.7%, H:3.3%, N:10.4%. 5,5'-Bis(N'-methyl-4, '-bipyridinium-N-methylene)- 2,2'-bipyridyl tetra(hexafluorophosphate) The white solid (0.30g. 0.38mmol) was dissolved in nitromethane (10cm 3 ) with stirring. To this was added methyl iodide (10cm 3 ) and the resultant solution heated to reflux for 24h. After cooling to room temperature the orange precipitate was collected by filtration and dried under vacuum. The solid was then dissolved in water (200cm 3 ) with warming and a saturated aqueous solution of ammonium hexafluorophosphate added until no further precipitation occurred. The solid was collected by filtration, washed with water (2 x 20cm 3 ) and dried under vacuum over silica gel to give the tetra- cationic receptor as a white solid (0.38g. 89%), m.p.>300°C. M.S. (FAB) [m/z-PFg-] + 959(w), [m/z-2PFg-] + 814, [m/z- 3PFg-] + 669. I.R. 3120/3100cm "1 (aromatic CH stretch), 1640/1600/1580cm -1 (C=C/C=N ring stretch) , 840cm -1 (br, PF 6 -) • ^H NMR (CD 3 CN, 270MHz) δ: 4.40 (6H, s, 4,4'N + -£U3), 5.93 (4H, s, bipy£H 2 ), 8.04 (2H, d, 3 J=8.2Hz, bipyH ) , 8.36 (4H, d, 3 J=6.6Hz, 4,4'H 3 ι), 8.42 (4H, d. 3 J=6.8Hz, 4 'H 3 ), 8.54 (2H, d, 3 J=8.1Hz, bipyH 3 ) , 8.83 (2H, ε, bipyHg), 8.84 (4H, d, 3 J=6.6Hz, 4.4'H 2 «), 9.02 (4H, d, 3 J=7.0Hz, 4.4Η 2 ) 13 C NMR (DMSO, 22.5MHz) 6: 48.02 (4,4'N + -£H 3 ) , 60.80 (bipy£H 2 ), 120.88, 126.12, 127.06, 130.48, 138.08, 145.95, 146.57, 148.16, 149.33, 149.82 and 155.22 (aromatic C) Analysis caluclated for C3 4 H3 F 24 NgP ; C:37.0%, H:2.9%, N:7.6%. Found C:36.4%, H:2.7%, N:77.7%. N, N'-Dimethyl-5,5'-bis(Ν'-dimβthyl-4,4'-bipyridinium- N-methylene)-2,2'bipyridyl hexa(hexafluorophosphate) (2) The tetra-cationic receptor (lOOmg, 0.091mmol) was dissolved in acetonitrile (5cm 3 ) . To this was added dimethyl sulphate (5cm 3 ) and the resultant solution heated at 80°C under nitrogen with stirring for 48h. After this time the solution was cooled to room temperature and dichloromethane (20cm 3 ) added to precipitate the product as a yellow solid. This was collected by filtration and washed with dichloromethane (2 x 10cm 3 ) . The solid was then dissolved in water (50cm 3 ) and a saturated aqueous solution of ammonium hexafluorophosphate added until precipitation ceased to occur. The product was collected by filtration, washed with water (2 x 10cm 3 ) and dried under vacuum over silica gel to give a white solid (2) (92mg, 71%), m.p.>300°C. M. S . (FAB) [m/z-2PFg_) + 1134, [m/z-3PFg_] + 989, [4, 4 ' - CH 3 ] + 171 I.R. 3150/3110cm -1 (aromatic CH stretch) . 1645/1605/1590cm -1 (aliphatic CH stretch) , 840cm -1 (br, PFg_) iH ΝMR (DMSO, 400MHz) δ: 4.13 (6H, s, 4,4'Ν + -£H3), 4.45 (6H, s, bipyN + -£I_3) , 6.30 (4H, s, bipyCH 2 ), 8.47 (2H, d, 3 J=8.1Hz, biρyH 4 ), 8.75 (4H, d, 3 J=5.7Hz, 4,4'H 3 .), 8.91 (4H, d, 3 J=5.7Hz, 4,4'H 3 ), 9.07 (2H, d, 3 J=7.9Hz, bipyH 3 ), 9.31 (4H, d, J=5.8Hz, 4,4'H 2 «), 9.49 (4H, d, J=5.8Hz, 4,4'H 2 ), 9.67 (2H, s, bipyHg) 13 C NMR (DMSO, 100.6MHz) δ: 47.94 and 48.20 (bipyN + - £H 3 and 4,4'N + -£H 3 ), 59.21 (bipy£H 2 ) , 126.17, 126.99, 130.75, 135.97, 142.87, 146.71, 146.88, 147.41, 147.77, 149.87 and 150.15 (aromatic C) . Analysis calculated for C3 H3gF3gNgPg; C:30.4%, H:2.7%, N:5.9%. Found C:24.8%, H:2.5%, N:5.9%. Anion Binding The receptor (2) displayed substantial shifts of the signals of the ****H NMR spectrum following the addition of one equivalent of tetrabutyl ammonium chloride. Analysis of the signals confirmed the formation of a complex between the receptor and the chloride ion. Example 3 N,N'-Bis(5'-methyl-2,2'-bipyridyl-5-mβthylene)-4,4'- bipyridinium bis(hexafluorophosphate) 5-Bromomethyl-5'-methyl-2,2'bipyridyl (300mg, 1.14mmol) and 4,4'-bipyridyl (84mg, 0.54mmol) were dissolved in acetonitrile (20cm3) with stirring. The solution was then heated to reflux for 24h. After cooling to room temperature the precipitate was collected by filtration, washed with dichloromethane (2 x 10cm3) and dried under vacuum. It was then dissolved in water (75cm 3 ) and a saturated aqueous solution of ammonium hexafluorophosphate added until precipitation ceased to occur. The solid wascollected by filtration, washed with water (2 x 10cm 3 ) and dried under vacuum over silica gel to give a white powder. (343mg, 78%), m.p.>275°C (decomp) . M. S . (FAB) [m/z+H] + 813 , [m/z-PFg-] + 667 , [m/z-2PFg-] + 522. I.R. 3120/3090cm -1 (aromatic CH stretch), 2920cm -1 (aliphatic CH stretch) , 1640/1600/1585cm -1 (C=C/C=N ring stretch) , 840cm -1+ (br ' PF g NMR (CD 3 CN, 270MHz) δ: 2.39 (6H, s, bipy£H 3 ) , 5.90 (4H, s, bipy£fl 2 ), 7.73 (2H, d, 3 J=8.1Hz, d, J=1.5Hz, bipyH , 7.98 (2H, d, 3 J=8.3Hz r d, J=2.2Hz, bipyH 4 ) , 8.33 (2H, d, 3 J=8.33Hz, bipyH 3 ι), 8.39 (4H, d, 3 J=7.0Hz, 4,4'H3), 8.48 (2H, d, 3 J=8.2Hz, bipyH3> , 8.52 (2H, m, bipyHg-), 8.78 (2H, d, 3 J=1.8Hz, bipyHg), 9.02 (4H, d, 3 J=7.0Hz, 4.4'H 2 ) 13 C NMR (DMSO, 22.5MHz) δ: 18.22 (bipy£U3) , 61.43 (bipy£H 2 ) , 120.70, 127.66, 130.06, 134.68, 138.19, 138.32, 146.32, 149.80, 150.09, 152.34 and 156.69 (aromatic C) . Analysis calculated for C3 H3oFι 2 N6 p 2' C:50.3%, H:3.7%, N:10.3%. Found C:50.1%, H:3.4%, N:10.2%. N,N'-Bis(N,N',5'-trimethyl-2,2'-bipyridinium-5- ethylene)-4,4'-bipyridinium bis(hexafluorophosphate) (3) The white powder (200mg. 0.25mmol) was dissolved in acetonitrile (20cm 3 ) under nitrogen. To this was added methyl iodide (10cm 3 ) and the resultant solution heated at reflux for 6 days. After cooling to room temperature the solvent was removed under reduced pressure and the red solid dissolved in water (50cm 3 ) . To this was added a saturated aqueous solution of ammonium hexafluorophosphate until precipitation ceased to occur. The precipitate was collected by filtration, washed with water (2 x 10cm 3 ) and dried under vacuum over silica gel. The solid was then dissolved in acetronitrile (15cm 3 ) , methyl iodide (10cm 3 ) added and the solution heated at reflux under nitrogen for 10 days. After cooling to room temperature the methyl iodide was removed under reduced pressure. Then a saturated solution of tetra- butyl ammonium chloride in acetonitrile was added dropwise until no further precipitation occurred. The solid was collected by filtration and washed with acetonitrile (2 x 10cm 3 ) . It was then dissolved in water (15cm 3 ) , a saturated aqueous solution of ammonium hexafluorophosphate added until no further precipitation occurred. The solid was collected by filtration, washed with water (2 x 10cm 3 ) and then dried under vacuum over silica gel. The resultant solid was dissolved in acetonitrile (10cm 3 ), dimethyl sulphate (5cm 3 ) added and the solution stirred at 75°C under nitrogen for 48h. After cooling to room temperature the precipitate was collected by filtration. It was then washed with acetonitrile (3 x 20cm 3 ) . The solid was dissolved in water (20cm 3 ) and a saturated aqueous solution of ammonium hexafluorophosphate added until no further precipitation occurred. The white solid was then collected by filtration, washed with water (3 x 10cm 3 ) and dried under vacuum over silica gel to give a white powder. (3) (158mg, 44%) . M.S. (FAB) [m/z-2PFg-] + 1161 -~H NMR (DMSO, 400MHz) δ: 2.64 (6H, s, bipy U3) , 4.05/4.16 (12H, 2s, bipyN + -£H3) , 6.29 (4H, s, bipy£H 2 ), 8.25 (2H, d, 3 J=8.1Hz, bipyH 4 ι) , 8.52 (2H, d, 3 J=8.2Hz, bipyH 4 ), 8.74 (2H, d, 3 J=8.1Hz, bipyH 3 ι), 8.89 (4H, d, 3 J=6.4Hz, 4,4'H 3 ), 9.06 (2H, d, 3 J=8.1Hz, bipyH 3 ), 9.36 (2H, s, bipyHgi), 9.52 (4H, d, 3 J=6.3Hz, 4,4'H 2 ), 9.67 (2H, s, bipyHg) 13 C NMR (DMSO, 100.6MHz) δ: 18.18 (bipy£H 3 ) , 47.38 and 47.98 (bipyN+-£H 3 ) , 59.42 (bipy£H 2 ) . 127.15, 129.80, 131.03, 135.03, 135.62, 139.94, 141.69, 143.75, 146.72, 146.91, 147.40, 149.11, 149.54 and 150.25 (aromatic C) . Analysis calculated for C38H 2 F3 N P .2H 0; C:30.7%, H:3.1%, N:5.6%. Found C:30.5%, H:2.9%, N:5.6%. Anion Binding The receptor (3) displayed substantial shifts of the signals of the -^-H NMR spectrum following the addition of one equivalent of tetrabutyl ammonium chloride and tetrabutyl ammonium bromide, respectively. Analysis of the signals confirmed the formation of complexes between the receptor and the chloride ion and the bromide ion, respectively.

Claims: CLAIMS 1. An ion-sensitive compound having the formula A n+ B n_ wherein A represents a cation' capable of forming a receptor-substrate complex with an anion, B represents one or more counter anions and n is an integer from 3 to 10, characterised in that the cation is an anion receptor represented by the formula R----Y-R 2 wherein Y is represented by the structure each q independently is an integer from 1 to 6; R 3 and R 4 are each independently H or a lower alkyl group having from 1 to 4 carbon atoms, or R 3 and R 4 taken together represent an ethylene bridging group; R and R 2 are each independently selected from organic cations and non-ionic organic groups wherein at least one of R 1 and R 2 is an organic cation and the combined ionic charge of R and R 2 is from 1 to 8; or, R 1 is H and R 2 is -X-Y-H wherein X is a linking group and Y is as defined above; or, R 1 and R 2 taken together represent -X-Y-X- wherein X and Y are as defined above. 2. A compound according to claim 1 wherein each q represents 1. 3. A compound according to claim 1 or claim 2 wherein R 3 and R 4 each represent methyl. 4. A compound according to any one of the preceding claims wherein both R 1 and R 2 are organic cations. 5. A compound according to claim 4 wherein R and R 2 are selected from pyridinium, bipyridinium, alkylammonium, pol (alkylammonium) , arylammoniu and poly(arylammonium) . 6. A compound according to claim 4 wherein R 1 and R 2 are selected from 2,2'-bipyridinium, 4,4'- bipyridinium and [ + N(R***- i ) 2 -R6] p -R 7 wherein each R**- 5 independently is hydrogen or an alkyl group of from 1 to 4 carbon atoms; R^ is an alkylene group of from 1 to 3 carbon atoms; R 7 is hydrogen or -N(R * 5)3 and p is an integer from 1 to 4. 7. A compound according to any one of claims 1 to 3 wherein X is selected from alkylene, arylene, and quaternised or unquaternised amine- or pol amine- containing groups such as alkylamino, aryla ino, aminoalkyleneamino, amino[pol (alkyleneamino) ] , bipyridyl and bipyridylamino. 8. A compound according to claim 7 wherein X is 4, '-bipyridinium or -[ + N(R-5) 2 -R^]p-N + (R^) 2 - wherein each R^ independently is hydrogen or an alkyl group of from 1 to 4 carbon atoms; R^ is an alkylene group of from 1 to 3 carbon atoms; R 7 is hydrogen or -N(R*5)3 and p is an integer from 1 to 4. 9. A compound according to claim 1 wherein the cation is N,N'-bis(N,N',5'-trimethyl-2,2'-bipyridyl-5- methylene)-N,N,N τ ,N'-tetramethyl-ethylene-diammonium; N, '-dimethy1-5,*5'-bis (N'-dimethy1-4,4'-bipyridinium- N-methylene)-2,2'bipyridyl; or, N,N'-bis (N,N',5'- trimethyl-2,2'-bipyridinium-5-methylene)-4,4'- bipyridinium.

Inventors: BEER PAUL D, MOORE CHRISTOPHER PETER, WEAR TREVOR JOHN, WHEELER JOHN W, BEER, PAUL, D., MOORE, CHRISTOPHER, PETER, WEAR, TREVOR, JOHN, WHEELER, JOHN, W.
Applicants: EASTMAN KODAK CO, KODAK LTD, EASTMAN KODAK COMPANY, KODAK LIMITED
Application year: 1992
Main classification: G01N24
IPC codes: C07D213, G01R33