SURFACE FUNCTIONALISATION

Abstract: A process for the surface functionalisation of a polymeric substrate, which process comprises: a) contacting the substrate with a diarylcarbene precursor, b) generating a carbene reactive intermediate from the diarylcarbene precursor so that it reacts with the substrate to functionalise the surface, and c) further functionalising the activated substrate obtained in step (b).

Description: SURFACE FUNCTIONALISATION The present invention relates to a process for the surface functiona sation of a polymeric substrate using diaryicarbenes as the reactive intermediates The invention in particular relates to a process for the surface functionahsation, for example dyeing, of substrates such as cotton, a variety of plastics, polystyrene, nylon, controlled pore glass, silica an ethylene polymer or polytetrafluoroethylene Dvestuffs which are used to colour natural and synthetic polvmers, via covalent modification, most commonly rely upon the presence of highly reactive groups which have been coupled to the chromophoπc species Examples include the Procion and Gibacron range of d\ es (which rely upon the reactivity of a chlorotπazinyl residue with nucleophihc residues on the substrate) the Remazol range of dyes (which rely on a vinvlsulfonyl residue as a nucleophihc acceptor) and the Dπmalon range of dyes (which contain an α-chloroacetyl residue as the reactive species) Modifications of these reactive entities have been developed, leading to other related dye classes (e g the Dπmarenes and Reactones, which use a tetrachloropyπmidine reactive unit, and the Pπmazin dyes, which use an acrylamide residue) Each of these reactive classes of dye have preferred substrates, although all contain aromatic or viny c groups which are particularly activated towards nucleophihc attack by suitable functionality on the substrate Development of this type of strategy still continues However, in addition to the requirement for nucleophihc functionality on the substrate (which would usually be hydroxyl or ammo groups), this approach generally requires vigorous conditions, such as high temperature or strongly basic media, for bond formation to occur An alternative technique whereby highly reactive carbene or nitrene species are generated from inert precursors under less harsh photolytic, and sometimes thermolytic, conditions has also been investigated for application to dyeing and other surface modifying processes of various natural and synthetic polymers The chemistry of carbenes and nitrenes is well documented, and these reactive entities are known to form covalent bonds with many types of functional group The application of these species to the surface modification of organic solids using different approaches both for the generation of the required carbenes or nitrenes, and for their reaction with the solid surface has been reported Interestingly, although nitrenes (often generated from an azide or sulfonylazide precursor under photolytic or thermolytic conditions) are more stable, and therefore less reactive, than their carbene analogues, they have been used much more widely for the dyeing of polymeric substrates French Patent No 1 500 512 discloses allowing carbenes to come into contact with an organic solid The preferred method for surface modification is to allow the volatilised carbene to come into contact with the polymer Inherent in this approach, however, aie limitations only volatile (1 e low molecular weight) carbenes and those stable to relatively high temperatures are applicable The application of carbenes generated from diazo compounds as suitable reactive dyes has been found to have important limitations for example the ease of generation of the required diazo precursor (D R Braybrook et al , / Photochem Photobwl A Chem, 1993, 70, 171) and the stability of the dye to the carbene generating process The present invention provides a process which may allow the surface functionahsation of materials which have hitherto been difficult to modify, for example glass or a variety of plastics The process of the present invention may also allow greater flexibility than known processes in which a single carbene insertion step introduces the desired functionality In addition, it is supposed that substrates which are dyed according to the process of the invention may exhibit superior wash- fastness to substrates dyed using existing processes due to a reduction in hydrolysable bonds on the surface of the substrate In a first aspect the present invention provides a process for the surface functionahsation of a polymeric substrate, which process comprises (a) contacting the substrate with a diarylcarbene precursor, (b) generating a carbene reactive intermediate from the diarylcarbene precursor so that it reacts with the substrate to functionahse the surface, and (c) further functiona sing the activated substrate obtained in step (b) In another aspect of the present invention steps (b) and (c) are combined The substrate may be any natural or synthetic polymeric substrate which is capable of reaction with a carbene reactive intermediate generated from a diarylcarbene precursor The molecular weight of the polymeric substrate may be selected according to the desired processability of the final product Typically the substrate is cotton, plastic, polystyrene, nylon, controlled pore glass, silica, an ethylene polymer or polytetrafluoroethylene By "diarylcarbene precursor", as used herein, is meant a diaryl species capable of generating a carbene reactive intermediate under the reaction conditions The diarylcarbene precursor must be such that the carbene reactive intermediate generated can react with the polymeric substrate and the activated substrate can be further functiona sed Preferably the diarylcarbene precursor is a compound of formula I (I) wherein R is Nr 1 or (CH 2 ) m Ν(R , )(R 2 ), Ar 1 is wherein Y is C, to C 4 alkoxy or N(R 3 )(R 4 ), R 3 and R 4 , which may be the same or different, are C, to C 4 alkyl, n is an integer of 0 to 3 , R' is C, to C 4 alkyl R 2 is phenyl, m is an integer of 1 to 4, and X is N 2 More preferably the diarylcarbene precursor is 4-([3,4- dιmethoxyphenyl]oxymethyl)phenyl phenyl diazomethane 1, 4-([3-N,N- dιethylamιnophenyl]-oxymethyl)phenyl phenyl diazomethane 2 or 4-([N-ethyl-N- phenyl-2-amιnoethyl]oxymethvl)phenyl phenyl diazomethane 3 Typically the diaryl diazomethane compounds are stable and may be stored at 0°C for extended periods Diarylcarbene precursors I and 2 may be prepared as shown in Scheme 1 4- Bromomethylbenzophenone, which can be prepared according to D D Tanner et al J Org Chem , 1980, 45, 5177 is first coupled with the desired arvl alcohol The resulting benzophenone may be converted to the hydrazone by treatment in refluxing ethanol overnight, followed by removal of the solvent and extraction into dichloromethane Oxidation of the hydrazone to the corresponding diazo diarylcarbene precursor may conveniently be performed with mercuric oxide in ether V Y 1 = OMe, Y 2 = OMe T Y 1 = H, Y 2 = NEt 2 (i) N 2 H 4 .H 2 0, EtOH (ii) HgO, Et 2 0, KOH, Na 2 S0 4 γ 1 Y 1 = OMe, Y 2 = OMe 2 Y 1 = H, Y 2 = NEt 2 Scheme 1 Diarylcarbene precursor 3 may be prepared similarly as shown in Scheme 2. Scheme 2 By "carbene reactive intermediate", as used herein, is meant a reactive species comprising a formally divalent carbon atom The carbene reactive intermediate is generated from the diarylcarbene precursor by treatment under conditions which result in an irreversible covalent reaction with the substrate Generally the carbene is generated by heating the substrate and pre ^ adsorbed diazo compound, or by irradiation Typically, the substrate is heated for the time required for decolourisation In one embodiment of the present invention part of the surface of the substrate is activated by selective heating or irradiation, for example by photoactivation using a laser This may allow the controlled and selective modification of a two-dimensional polymer surface and may be useful in two- dimensional data storage such as CD data storage. The activated substrate obtained in step (b) is further functionalised. By "functionalise", as used herein, is meant the introduction of a or another chemical functional group, which exhibits desirable physical or chemical properties, by irreversible covalent attachment. The activated substrate may be further functionalised by, for example, a dye, fluorescent brightener, UN-absorber, antistatic agent, flame retardant, surface finish, non-linear optical function, chelating function, electrically conducting function, magnetic function or polarising function. The dye may be any suitable diazonium compound, for example a commercially available diazonium compound which may be selected to obtain the desired colour such as red, yellow, orange or blue. The colour may be altered in some cases by adjustment of pH of the final polymer sample by suitable treatment with acid or base. Examples of suitable diazonium compounds include those of formulae II, III or IV (ll) (III) (iv) wherein R 3 and R 6 , which mav be the same or different, are NO ^ or SO^a, R 7 and R s , which may be the same or different, are C, to C 4 alkoxy, preferably methoxy, wherein R 9 is C, to C alkyl and q is an integer of 0 to 3, preferably 0, and X is fluorine, chlorine, bromine or iodine The activated substrate may also be functionalised by, for example, introduction of a phthalocyamne functional group The process of the invention may find application in, for example, the dye industry, or combinatorial or polymer chemistry More particularly the process of the present invention may find application in the preparation of immobilised catalysts, immobilised colours and dyes, photoelectric/solar cells, conducting (including photoelectric and semiconducting) polymers, magnetic polymers and optical recording and non-linear optical devices The process of the present invention may also be used in the preparation of biocidal or biostatic fabrics and plastics which have applications in, for example water purification, medical and military clothing (where biocidal activity would help to minimise the transfer of infective agents or infections due to injury in the field) and surface anti-fouhng of, for example, ship hulls, showers or tubing The activated substrate obtained in step (b) of the process of the present invention may be functionalised by, for example, a chemical functional group comprising an antibiotic, a heavy metal such as silver, copper or zinc, a quaternary ammonium salt, a phosphonium salt, an oxidising agent such as an N-halamine or precursor thereof for example chloramine, chlorine, hydrogen peroxide or iodine, or a phenolic group According to the process of the present invention the polymeric substrate may be, for example, a polymeric thread or a finished textile The surface functionalised substrates prepared bv the process of the present invention may be durable to repeated use and laundry, and may be regenerable For example, the activated substrate obtained in step (b) may be functionalised using a urea hydroperoxide functional group which would be regenerable by treatment with hydrogen peroxide or an N-halamine functional group which would be regenerable with a chlorine solution such as hypochloπte bleach In a further aspect the present invention provides diarylcarbene precursors of formula I as defined above The Examples which follow further illustrate the present invention Examples UV spectra were recorded on a Perkin Elmer 555 UV-visible spectrometer IR spectra were obtained as Nujol mulls, or as liquid films, and were recorded on a Perkin Elmer 781 spectrophotometer broad (br), weak (w), medium (m) and strong (s) bands are reported Η NMR spectra were recorded on a Vaπan Gemini 200 MHz spectrometer using the solvents (CDC1, or (CD 3 ) 2 CO) as internal standards Multiplicities are recorded as s (singlet), d (doublet), t (triplet), q (quartet) and m (multiplet) Mass spectra were recorded on VG Analytical Ltd ZAB IF or MM30F mass spectrometers(probe ammonia chemical lomsation (CI NHN positive argon fast atom bombardment (FAB) and electron impact (El)) Melting points were recorded on a Stuart Scientific SMP1 melting point machine and are uncorrected Flash chromatography was performed using Merck silica gel Eluants used were as indicated in the text and the following solvents were dried and purified before use according to standard procedures dichloromethane was refkixed and distilled over calcium hydride, ethyl acetate was distilled and the first 20% of the distillate was discarded petroleum ether (b p 60-80°C) was distilled and the first 20% of the distillate was discarded, THF was refluxed and distilled over sodium benzophenone ketyl under an atmosphere of argon When necessary, solvents were degassed using a water pump for 15 mm Thin laver chromatographv was performed on Merck 60 F 254 Art 5554 precoated silica plates and product spots were visualised under UV conditions at 254 nm Benzophenone hydrazone was purchased from Aldπch Preparation of Diarylcarbene Precursors General Method A for the formation of benzophenone hydrazones. The required benzophenone was refluxed in ethanol and hydrazine hydrate overnight The solvent was removed in vacuo and the residue dissolved in DCM, washed with water, dried and concentrated under vacuum The hydrazones, which were obtained as inseparable mixtures of the syn- and anti- isomers, were then used without further purification General Method B for the formation of diphenyl diazomethanes The required benzophenone hydrazone was dissolved in Et 2 O and stirred vigorously with yellow mercuric oxide (1 2 eq), sodium sulphate and saturated KOH in ethanol Stirring was continued overnight and the mixture was filtered through Ce te® Excess solvent was removed under vacuum and the product was used without further purification 4-Bromomethylbenzophenone A stirred mixture of 4-methylbenzophenone (15 02 g, 76 6 mmol) and N- bromosuccinimide (14 2 g, 79 8 mmol) in CHC1 3 (100 cm 1 ) was heated under gentle reflux for 18h with a 100W bulb shining 2 cm from the flask The reaction mixture was washed with water, dried (MgSO 4 ) and solvent was removed in vacuo The resulting solid was then washed with Et 2 O to remove any starting material to leave the product as a white solid (15 07 g, 71 5%, mp 1 10-1 12°C(ht 1 10-1 1 1°), δ„ (200 MHz, CDCU) 4 55 (2 H, s, CH ^ Br), 7 46-7 70 (5 H, m, ArH), 7 80-7 90 (4 H, m, ArH o- to C=O), m/z 277 ([M 1 Br+H] + , 25%) and 275 ([M 79 Br+H] + , 25%), 197 (100%) 4-([3,4-Dimethoxyphenyl]oxymethyl)benzophenone 1 To 3,4-dιmethoxyphenol (1 69 g, 1 1 mmol) in THF was added ΝaH (60% dispersion in oil, 1 2 eq , 0 53 g) and stirring continued for 1 hour 4-Bromomethyl benzophenone (3 01 g, 1 1 mmol) was then added to the solution and stirring continued for a further 24 hours The solution was concentrated in vacuo, diluted with DCM, washed with citric acid (10% aq ), ΝaOH (IN) dried and solvent removed under vacuum The residue was then purified by column chromatography, eluting with petrol (40-60) EtOAc 9 1 yielding the product as a white solid (2 58 g, 68%) (Found C, 75 73, H, 5 96 C 22 H 20 O 4 requires C, 75 84, H, 5 79%), mp 74- 75°C, Rr=0 23 (Petrol EtOAc 4 1), δ H (250 MHz, CDC1 3 ) 3 82 (3 H, s, OCH 3 ), 3 86 (3 H, s, OCH 3 ), 5 10 (2 H, s, CHj), 6 47 (1 H, dd, J 9, 1, ArH/?- to OMe), 6 65 (1 H, d, J 1, ArH o- to 2 OR), 6 80 (1 H, d, J9, ArH m— to 2 OR), 7 47-7 75 (5 H, m, ArH), 7 80-7 91 (4 H, m, ArH 0- to C=O), δ c (50 3 MHz, CDC1 3 ) 55 8 (OCH 3 ), 56 4 (OCH 3 ), 69 9 (CH 2 O), 101 2 and 104 0 (ArCH o- to OCH 2 Ar), 111 7 (ArCH m-to OCH 2 Ar), 127 0, 128 3, 130 0 and 130 3 (ArCH o- and -t CO), 132 5 (ArCH p- to C=O), 137 0 and 137 5 (4° ArCCO), 141 9 (ArCCH 2 O), 143 8 (4° ArCOCH 2 ), 149 9 (4° ArCOMe ?- to OCH 2 Ar), 153 0 (4° ArCOMe m- to OCH 2 Ar), 196 3 (C=O), m/z (APCI + ) 349 ([M+H]\ 100%) 4-(|3,4-DimethoxyphenyI]oxymethyl)benzophenone hydrazone The benzophenone 1' (1 52 g, 4 36 mmol) was reacted with hydrazine hydrate according to General Method A yielding the hydrazone as a yellow oil (1 50g, 95%), δ„ (200 MHz, CDC1,) 3 76, 3 77, 3 79 and 3 81 (6 H, 4* s, OCIL), 4 91 and 5 03 (2 H, 2* s, CH,), 5 47 (2 H, br s, NH,), 6 40 and 6 46 (1 H, 2* dd, J 9, 1 , ArH/ to OMe), 6 55 and 6 60 (1 H, 2* d, J 1, ArH_o- to 2 OR), 6 6S and 6 73 (1 H, 2* d, J 9, ArH - to 2 OR), 7 20-7 60 (9 H, m, ArH), δ r (50 3 MHz, CDCl,) 55 7 (OCHN 56 3 (OCHN 70 0 (CH 2 O), 101 2 and 104 0 (ArCH o- to OCH 2 Ar), 1 1 1 8 (ArCH w-to OCH 2 Ar), 126 4, 126 5, 127 3, 128 0, 128 1, 128 5, 128 8, 128 9, 129 1 and 129 4 (ArCH o- and m—to C=N), 132 5 and 132 9 (ArCH/;- to C=N), 136 9, 137 9, 138 2 and 138 4 (4* ArCC=N), 143 6 and 143 8 (4° ArC_CH 2 O), 148 1 (4° ArCOCH 2 ), 149 8 and 149 9 (4° ArCOMe p- to OCH 2 Ar), 153 2 (ArCOMe m-to OCH 2 Ar), m/z (APCI + ) 363 ([M + H] + , 100%) 4-([3,4-DimethoxyphenyI]oxymethyI)phenyl phenyl diazomethane 1 The above benzophenone hydrazone (1 50 g, 4 14 mmol) was reacted with mercuric oxide and sodium sulphate according to General Method B yielding the diazomethane as a purple oil (1 35 g, 91%) (Found C, 73 85, H, 5 33, N, 7 31 C 22 H 20 N 2 O 3 requires C, 73 32, H, 5 59, N, 7 77%), v ^ JfilmVcm- 1 2038 (s), 1595 (m), 151 1 (s), δ H (500 MHz, CDCI 3 ) 3 85 (3 H, s, OCH 3 ), 3 87 (3 H, s, OCH 3 ), 5 02 (2 H, s, CHa), 6 49 (1 H, dd, J9, 1, ArH p- to OMe), 6 62 (1 H, d, J 1, ArHp- to 2 OR), 6 80 (1 H, d, J9, ArH rø-to 2 OR), 7 16-7 49 (9 H, m, ArH}, δ c (125 8 MHz, CDC1 3 ) 55 8 (OCH 3 ), 56 4 (OCH 3 ), 70 2 (CH 2 O), 101 2 and 104 0 (ArCH o- to OCH 2 Ar), 111 6 (ArCH m-to OCH 2 Ar), 125 1, 125 2, 128 5 and 129 1 (ArCH o- and m-to C=N), 125 7 (ArCH/?- to C=N), 129 3 and 129 4 (4° ArCC=N), 134 4 (4° ArCCH 2 O), 143 6 (4° ArCOCH 2 ), 149 8 (4° ArCOMep- to OCH 2 Ar), 153 3 (4° ArCOMe m- to OCH 2 Ar) 4-([3-N,N-DiethyIaminophenyI]oxyrnethyI)benzophenone 2' 3-NN-Dιethylamιnophenol (3 03 g, 18 4 mmol, 1 2 eq) in THF (20 cm 3 ) was treated with ΝaH (60% dispersion in oil, 524 mg, 13 1 mmol, 1 4 eq) and stirred at 20°C for 1 hour 4-Bromomethylbenzophenone (4 21 g, 15 3 mmol) was then added and stirring continued for 72 hours Excess solvent was removed in vacuo and the residue diluted with DCM, washed with water and NaHCO 3 solution (sat ), dried (MgSO 4 ) and solvent removed under vacuum The resulting oil was purified by flash chromatography, eluting with petroleum (bp 40-60°C) EtOAc (9 1), to give the desired product as a yellow oil (4 29 g, 65%), R r = 0 51 (4 1, petrol EtOAc) (Found C, 79 99, H, 7 13, N, 5 23 C 24 H 25 NO 2 requires C, 80 19, H, 7 01 , N, 3 90%, v m x (film)/cm ' 1657 (s), 1610 (s), δ„ (500 MHz, CDC1,) 1 17 (6 H, t, 77, CH 3 ), 3 35 (4H, q, 77, CH HN 5 16 (2 H, s, ArCftO), 6 27-6 40 (3 H, m, ArH ?- and/?- to NEt 2 ), 7 15 (1 H, dd, .77, 7, ArH m- to NEt 2 ), 7 45-7 66 (5 H, m, ArH}, 7 80-7 89 (4 H, m, ArH o- to CO), δ c (125 8 MHz, CDC1,)12 6 (CH 3 ), 44 4 (NC_H 2 CH 3 ), 69 2 (ArCH 2 O), 99 1, 100 8 and 105 4 (ArCH o- and /?- to NEt 2 ), 127 0, 128 3, 130 0 and 130 4 (ArCH), 132 4 (ArCH/?- to CO), 136 9 and 137 6 (4° ArCCO), 142 3 (4° ArCCH 2 O), 149 2 ArCNEt 2 ), 159 9 (4° ArCOCH 2 ), 196 4 (CO), m/z (APCF) 360 ([M + H]\ 100%) 4-([3-N,N-DiethyIaminophenyl]oxymethyl)benzophenone hydrazone The benzophenone 2 1 (1 76 g, 1 95 mmol) was reacted with hydrazine hydrate according to General Method A yielding the hydrazone as a colourless oil (1 31 g, 72%), (Found C, 76 26, H, 7 30, Ν, 12 47 C 24 H 27 Ν 3 O requires C, 77 18, H, 7 29, N, 11 25%), v max (film)/cm ' 1605 (m), δ H (200 MHz CDC1 3 ) 1 24-1 34 (6 H, m, CH 3 ), 3 39-3 54 (4 H, m, 5 16 and 5 24 (2 H, 2* s, ArCE O), 5 61 (2 H, br s, NNHs), 6 45-6 52 (3 H, m, ArH o- and/?- to NEt 2 ), 7 25-7 77 (10 H, m, ArH), δ c (50 3 MHz, CDC1 3 ) 12 7 (CH 3 ), 44 5 (NCH 2 CH 3 ), 69 6 and 69 7 (ArCH 2 O), 99 4 and 99 5, 101 1 and 101 2, 105 6 and 105 7 (ArCH o- and/?- to NEt 2 ), 126 8, 127 0, 127 7, 128 1, 128 4, 128 5, 128 9, 129 2, 129 5, 129 8, 130 3, 130 4, 132 8, 133 3, 137 7, 138 5, 138 7, 138 7 and 138 9 (ArCH, 4° ArC_C=N and 4° ArCCH 2 O), 148 8 (C=NNH 2 ), 149 5 (4° ArCNEt 2 ), 160 6 (4° ArCOCH 2 ), m/z (APCr) 374 ([M + H]\ 15%), 209 (100), 195 (50), 178 (75) 4-(|3-N,N-DιethyIamιnophenyi|oxymethyI)phenyl phenyl diazomethane 2 The above benzophenone hydrazone (1 30 g, 3 49 mmol) was stirred vigorously with yellow mercuric oxide (1 40 g, 6 5 mmol), anhydrous sodium sulphate (2 00 g, 14 1 mmol) in diethyl ether (33 cm 3 ) and saturated KOH in ethanol (1 cm 3 ) for 18 hours The solution was filtered through Cehte ® and solvent removed in vacuo yielding the product as a red oil ( 1 22 g, 94%), v max (film)/cm i- 2037 (s), 1612 (m), δ„ (200 MHz, CDC1,) 1 27 (6 H, m, CH,), 3 44 (4 H, m, ΝCHjCH,), 5 15 (2 H, s ArCHjO), 6 42-6 50 (3 H m ArH o- and /?- to ΝEt 2 ), 7 21-7 55 (10 H, m ArH), δ f (50 3 MHz, CDC1,) 12 8 (CH,). 44 5 (NCH 2 CH,), 69 6 (ArCH 2 O), 99 3, 101 0 and 105 5 (ArCH o- and ?- to NEt 2 ), 128 2, 128 6, 128 7, 129 2 and 129 3 (ArCH o- and m— o C=N and AiCH m-to NEt,), 130 0 (ArCH ?- to C=N), 132 5 and 133 0 (4° ArCC=N), 135 0 (4° ArCCH 2 O), 149 2 (4° ArCNEt 2 ), 160 3 (4° ArCOCH,) 4-([N-Ethyl-N-phenyI-2-aminoethyl]oxymethyI) benzophenone 2-(N-Ethylamhno)ethanol (3 03 g, 18 4 mmol, 1 2 eq) in THF (20 cm 3 ) was treated with ΝaH (60% dispersion in oil, 524 mg, 13, 1 mmol, 1 4 eq) and stirred at 20°C for 1 hour 4-Bromomethylbenzophenone (4 21 g, 15 3 mmol) was then added and stirring continued for 72 hours Excess solvent was removed m vacuo and the residue diluted with DCM, washed with water and ΝaHCO 3 solution (sat ), dried (MgSO 4 ) and solvent removed under vacuum The resulting oil was purified by flash chromatography, eluting with petroleum (bp 40-60°C) EtOAc (9 1), to give the desired product as a yellow oil (4 36 g, 80%), R f = 0 54 (4 1, petrol EtOAc) (Found C, 78 34, H, 6 86, N, 5 29 C 24 H 25 NO 2 requires C, 80 19, H, 7 01, N, 3 90%), v m „ (film/cm ' 1658 (s), 1598 (s), 1506 (s), δ H (200 MHz, CDC1 3 ) 1 22 (3 H, t, .77, CFQ, 3 49 (2 H, q, J 7, 6 69-6 79 (3 H, m, ArH o- and p- to NR 2 ), 7 28 (2 H, dd, J 7, 7, ArH w-to NR 2 ), 7 46-7 68 (5 H, m, ArH), 7 80-7 88 (4 H, m, ArH ø- to CO), δ c (50 3 MHz, CDCU) 12 2 (CH 3 ), 45 5 (NCH 2 CH,), 50 1 (NCH 2 CH 2 O), 68 5 (NCH 2 CH 2 O), 72 2 (ArCH 2 O), 1 1 1 8 (ArCH o- to NR 2 ), 1 15 8 (ArCH /?- to NR 2 ), 127 0, 128 3, 129 3, 130 0 and 130 3 (ArCH o- and w- to CO and ArCH m- to NR 2 ), 132 4 (ArCH /?- to CO), 136 8 and 137 7 (4° ArCCO), 143 2 (4° ArCCH 2 O), 147 7 (4° ArCNR 2 ), 196 4 (CO), m/z (APCI + ) 360 ([M + H]\ 30%), HRMS C 24 H 26 O 2 N requires 360 1963, found 360 1963 4-([N-EthyI-N-phenyI-2-aminoethyl]oxymethyl) benzophenone hydrazone The above benzophenone (701 mg, 1 95 mmol) was reacted with hydrazine hydrate according to General Method A yielding the hydrazone as a colourless oil (710 mg, 97%),v M X (film)/cm ' 1598 (s), 1506 (s), δ„ (500 MHz, CDC1,) 1 27 and 1 31 (3 H, 2* t, / 7, CH,), 3 52 and 3 57 (2 H, 2* q, J 7, CFLCH,), 3 60-3 87 (4 H, m, ΝCH 2 CH 2 O), 4 63 and 4 71 (2 H, 2 X s, ArCH^O), 5 57 (2 H, br s, NNIL), 6 76- 6 87 (3 H, m, ArH o- and ?- to NR 2 ), 7 30-7 42 (7 H, m, ArH), 7 53-7 64 (4 H, m, ArH o- to C=N), δ c (125 8 MHz, CDC1 3 ) 12 0 (CH 3 ), 45 1 and 45 2 (NCH 2 CH 3 ), 49 8 (NCH 2 CH 2 O), 67 8 and 68 1 (OCH 2 CH 2 N), 72 6 and 72 7 (ArCH 2 O), 1 11 5 and 1 1 1 6 (ArCH o- to NR 2 ), 1 15 5 and 1 15 6 (ArCH ?- to NR 2 ), 126 2, 127 1, 127 7, 127 8, 128 1, 128 5, 128 6, 128 9, 129 0 and 129 1 (ArCH), 131 9 and 132 8 (4° ArCCH 2 O), 137 7, 137 8, 138 3 and 138 9 (4° ArCC=N), 147 5 (4° ArCNR 2 ), 148 1 (C=N H 2 ), m/z (APCI + ) 374 ([M + H] + , 5%), 357 (5%), 209 (100%) 4-([N-Ethy!-N-phenyI-2-aminoethyl]oxymethyl)phenyl phenyl diazomethane 3 The above benzophenone hydrazone (701 mg, 1 88 mmol) was reacted with mercuric oxide and sodium sulphate according to General Method B yielding the diazomethane as a purple liquid (690 mg, 99%) (Found C, 78 06, H, 6 89, Ν, 12 36 C 24 H 25 Ν 3 O requires C, 77 60, H, 6 78, N, 11 31%), v max (film)/cm-' 2037 (s), 1559 (m), δ H (500 MHz, CDCl 3 ) 1 26-1 32 (3 H, m, CH 3 ), 3 50-3 80 (6 H, m, NCH^CH, and NCfcLCFkO), 4 65 (2 H, s, ArCH )), 6 78-6 86 (3 H, m ArH o- and ?- to NR 2 ), 7 28-7 65 (1 1 H, m ArH), δ c (125 8 MHz, CDC1,) 12 1 (CH 3 ), 45 3 (NCH 2 CH 3 ), 500 (NCH 2 CH 2 O), 679 (OCH 2 CH 2 N), 728 (ArCH 2 O), 1117 (ArCH - to N 2 ), 1156 (ArCH/?- to NR 2 ), 1250, 1255, 1263, 1283, 1284, 1287, 1290, 1291 and 1292 (4° ArC and ArCH), 1357 (4° ArCCH 2 O), 1477 (4° ArCNR 2 ), m/z (APCI + ) 344 ([M - N 2 ]\ 20%), 209 (100) Activaikm and Functionalisation of Substrates 2-SuIphonyl-4-nitrobenzene diazonium chloride (0.1M aq) To a suspension of 2-amino-5-nitrobenzene sulphonic acid, sodium salt (2.40 g, 10 mmol) in iced water (50 cm 3 ) and HCI (10 N, 5 cm 3 ), NaNO 2 (1 M, 1 1 cm 3 ) was slowly added and stirred vigorously for 5 minutes whilst maintaining the temperature at 0°C. The solution was made to pH 4 with sodium acetate and diluted to 100 cm', the diazonium ion was then used without further purification at 0°C within one hour of formation. Functionalisation of Substrates Solutions of the appropriate diazomethane or benzophenone (10-200 mg) in diethyl ether (1-2 ml), or pure ether, were applied to three samples of the appropriate polymeric substrate (100mg-5g) and the solvent allowed to evaporate at room temperature. One of these samples was taken out and kept aside. The rest of the substrate was then heated, in foil or conical flasks, with a heat gun for the time required to decolourise the substrate which had been treated with the diazocompound. Another sample from each batch of treated polymer was kept aside at this point. The remaining substrate was then moistened with ethanol (2 cm 3 ) and a suspension of the diazonium salt (50 cm 3 , 0.1 M) was added and the mixture stirred overnight. The substrate was then removed, washed with water, hot water and soap, acetone, HCI (IN), NaOH (IN), water and acetone until no further colour leached out of the substrate into the liquid. The substrate was allowed to dry to obtain the final sample. The use of compounds 1 to 3 for the modification of a range of substrates (cotton, controlled pore glass, polystyrene XAD-40, silica and nylon membrane) was investigated. Treating each substrate with the diazo compounds aad heating to generate the corresponding carbene gave the surface-modified substrate; this effectively generated an activated polymer with the electron-rich aromatic residue attached (Scheme 3). Treatment of the activated polymer with the diazonium salt derived from 2-amino-5-nitrobenzene sulphonic acid then gave the corresponding azo-dyed material. Scheme 3 For each substrate, nine controls were run simultaneously (each polymer was treated with the solvent only, the diazo compounds and their corresponding benzophenones, either just with the native polymer, with the native polymer and heating, and with the native polymer, heating and then adding the diazotisation reagent), in order to verify that any colouration that arose was due to irreversible bond formation, resulting from carbene insertion, and not merely physical adsorption, and the results are indicated in Table 1. The sample numbering scheme for the controls is indicated; samples 1-3 indicate that colouration is not derived simply from modification of the polymer alone in the heating and diazo treatment process, samples 4-6 indicate that the colouration derives from the diazo coupling reaction (shown in Scheme 3) but that this colour washes out, since there was no carbene insertion reaction when the benzophenones were used as the substrate. Samples 7-9 indicate that treatment with both the carbene and diazo coupling agents leads to irreversible colouration. TABLE 1: DYEING OF VARIOUS SUBSTRATES WITH COMPOUNDS 1, 2 OR 3 COTTON: Mercerised Woven Cotton POLYSTYRENE: Amberlite XAD-4 Non-ionic Pol meric Adsorbant (ex Aldrich Cat No 21,648-8) CONTROLLED PORE GLASS: (ex CPG Inc) FLASH SILICA: (ex Merck) No heat was required for generation of the carbene Scale:

Claims: CLAIMS A process for the surface functionahsation of a polymeric substrate, which process comprises (a) contacting the substrate with a diarylcarbene precursor, (b) generating a carbene reactive intermediate from the diarylcarbene precursor so that it reacts with the substrate to functionalise the surface, and (c) further functionahsing the activated substrate obtained in step (b) A process according to claim 1 , wherein steps (b) and (c) are combined A process according to claim 1 or 2, wherein the substrate is cotton, plastic, polystyrene, nylon, controlled pore glass, silica, an ethylene polymer or polytetrafluoroethylene A process according to any one of the preceding claims, wherein the diarylcarbene precursor is a compound of formula I wherein R is Ar 1 or (CH 2 ) m N(R')(R 2 ), Ar 1 is wherein Y is C, to C 4 alkoxy or N(R )(R 4 ), R 3 and R , which may be the same or different, are Cj to C 4 alkyl, n is an integer of 0 to 3, R 1 is C, to C 4 alkyl, R 2 is phenyl, m is an integer of 1 to 4 and X is N 2 . 5. A process according to claim 4, wherein R is N-ethyl-N-phenyl-2-aminoethyl, 3,4-dimethoxyphenyl or 3-N,N-diethylaminophenyl and X is Ν 2 . 6. A diarylcarbene precursor as defined in claim 4 or 5. 7. A process according to any one of the preceding claims, wherein the carbene reactive intermediate is generated by heating. 8. A process according to any one of the preceding claims wherein the activated substrate obtained in step (b) is further functionalised by a dye, fluorescent brightener, UN-absorber, anti-static agent, flame retardant, surface finish, non-linear optical function, chelating function, electrically conducting function, magnetic function or polarising function. h A process according to claim 8, wherein the dye is a diazonium compound. 10. A process according to claim 9, wherein the dye is a diazonium compound of -10. any one of formulae II, III or IV (ID (ill) (IV) wherein R 5 and R 6 , which may be the same or different, are NO 2 or SO 3 Na; R 7 and R 8 , which may be the same or different, are Cj to C 4 alkoxy; Ar 2 is wherein R 9 is C, to C 4 alkyl and q is an integer of 0 to 3; and X is fluorine, chlorine, bromine or iodine. 1 1. A process according to claim 10, wherein R 7 and R 8 are methoxy and q is 0. 12. A surface functionalised substrate prepared by the process according to any one of claims 1 to 5 or 7 to 1 1.

Inventors: AWENAT KARIM, EBENEZER WARREN, MOLONEY MARK GERARD, AWENAT, KARIM, EBENEZER, WARREN, MOLONEY, MARK, GERARD
Applicants: AWENAT KARIM, EBENEZER WARREN, ISIS INNOVATION, MOLONEY MARK GERARD, AWENAT, KARIM, EBENEZER, WARREN, ISIS INNOVATION LIMITED, MOLONEY, MARK, GERARD
Application year: 1999
Main classification: C07C245
IPC codes: B05D3, C07C245, C08J7, D06B1, D06P1, D06P5