Crystal and Molecular Structures of N-Phenylmaleimide and N-Phenyl-2,3-dimethylmaleimide

N-Phenylmaleimide and N-phenyl-2,3-dimethylmaleimide have been synthesized and structurally characterized by X-ray diffraction. The crystal structure of the second compound proves that condensation of PhNH2 with 2,3-dimethylmaleic anhydride gives, through a one step mechanism, N-phenyl-2,3-dimethylmaleimide and not the corresponding isomaleimide

The influence of the chemical structure on the properties of molecularly imprinted crosslinked polymers

U radu je opisana sinteza monomera N-metakril-N,N\u27-dicikloheksiluree (MA-DCU) i N-metakril-N,N\u27-diizopropiluree (MA-DiPrU) te polimerizacija s etilen-glikol dimetakrilatom (EDMA). Polimerizacija je provedena u butanonu s benzoil-peroksidom (Bz2O2) do visoke konverzije. Dobiveni su umreženi kopolimeri netopljivi u organskim otapalima. Neovisno o sastavu, kopolimeri se razgrađuju dvostupnjevitim mehanizmom pri temperaturama od 180 °C do 450 °C uz izdvajanje cikloheksilizocijanata (C6H11NCO), odnosno izopropilizocijanata (C3H7NCO) pri temperaturi od 180 °C do 250 °C. Ostatak nakon izdvajanja izocijanata je termički stabilan nanoporozni umreženi kopolimer metakril-cikloheksilamida (MA-CHA), odnosno metakril-izopropilamida (MA-iPrA) s EDMA. Ti se kopolimeri razgrađuju u jednom stupnju pri temperaturama od 280 °C do 450 °C. Sintetizirani su i neporozni kopolimeri MA-CHA, odnosno MA-iPrA s EDMA (modelni kopolimeri) radi usporedbe svojstava s odgovarajućim nanoporoznim kopolimerima.The present paper describes the synthesis of monomers N-methacryl-N,N’-dicyclohexylurea (MA-DCU) and N-methacryl-N,N’-diisopropylurea (MA-DiPrU) and their polymerization with ethylene glycol dimethacrylate (EDMA). Polymerization were carried out in butanone by using dibenzoyl-peroxide (Bz2O2) up to high conversion. All prepared copolymers are insoluble in common organic solvent. Crosslinked copolymers decompose thermally at temperatures from 180 °C to 450 °C under the separation of cyclohexylisocyanate (C6H11NCO) or isopropylisocyanate (C3H7NCO) at temperature between 180 °C and 250 °C. Residues after the removal of isocyanate are thermally stable nanoporous crosslinked copolymers of methacryl-cyclohexylamide (MA-CHA) or methacryl-isopropylamide (MA-iPrA) with EDMA, which decompose by a one-step mechanism between 280 °C and 450 °C. Nonporous model copolymers of MA-CHA and MA-iPrA with EDMA were also prepared in order to compare their properties with the properties of corresponding nanoporous copolymers

A new approach to the preparation of molecularly imprinted polymers

U radu je opisana sinteza i polimerizacija akrilnih monomera koji imaju dicikloheksilureu (DCU) u bočnom lancu. Polimerizacijom akril-DCU s etilen-glikol dimetakrilatom (EDMA) do visoke konverzije, u butanonu s benzoil-peroksidom (Bz2O2), pri temperaturi od 70 °C sintetizirani su umreženi kopolimeri različitog sastava. Pri uvjetima kontrolirane termičke razgradnje u TG analizatoru, u temperaturnom području od 100 °C do 500 °C u struji dušika, kopolimeri se razgrađuju dvostupnjevitim mehanizmom. U prvom stupnju, od 180 °C do 250 °C, izdvaja se cikloheksilizocijanat. Ostatci nakon uklanjanja izocijanata termički su stabilni molekulski tiskani (nanoporozni) kopolimeri akril-cikloheksilamida (A-CHA) s EDMA, koji se razgrađuju u jednom stupnju pri temperaturi od 300 °C do 450 °C. Radi usporedbe svojstava molekulski tiskanih, nanoporoznih kopolimera poli(A-CHA-ko-EDMA) s odgovarajućim neporoznim kopolimerima, sintetizirani su neporozni kopolimeri A-CHA s EDMA pri navedenim uvjetima.This paper describes the synthesis and polymerization of acrylic monomers which contain dicyclohexylurea (DCU) as a pendant group. Crosslinked copolymers of these monomers with ethylene glycol dimethacrylate (EDMA) were prepared under the standard free radical initiated polymerization with dibenzoyl-peroxide (Bz2O2) as initiator, in butanone at 70 °C, up to high conversion. It was found that copolymers, regardless of the ratio of comonomers in the feed, thermally decompose by the two-step mechanism under the separation of almost quantitative yield of cyclohexylisocyanate, in the temperature range from 180 °C to 250 °C. The residues left by the removal of isocyanate were thermally stable crosslinked molecularly imprinted copolymers of acryl-cyclohexylamide (A-CHA) with EDMA, which decompose by a one-step mechanism between 300 °C and 450 °C. In order to compare the properties of nanoporous crosslinked copolymers of A-CHA with EDMA with those of nonporous poly(A-CHA-co-EDMA) of the same molar composition, nonporous copolymers were prepared by the polymerization of A-CHA with EDMA under the conditions described above

Crystal and Molecular Structure of (S)-a-(pCyanobenzenesulphonamido)-B- propiothiolactone, C10H8N203S2

Crystals of the title compound are monoclinic, space group P21, with a = 1.0018(2), b = 0.9722(2), c = 0.6262(1) nm, fJ = 102.32(1)° and Z = 2. The structure was solved by direct methods using 1113 reflections with I 2\u27: 20 (I) and refined to a conventional R index of 0.051. The heterocyclic four-membered ring is bent and has a puckering angle of 18.7(7)°. The dihedral angle between the best planes of the B-propiothiolactone and benzene ring is 70.2(3)°. Discrete molecules are connected along the b axis by intermolecular hydrogen bonds N--H ... O of 309.5(9) pm

Crystal and Molecular Structure of (S)-a-(p-Bromobenzenesulphonamido)-B-propiothiolactone

(S)-a-(p-Bromobenzenesulphonamido)-{J-propiothiolactone, C9H8N03S2Br, crystallizes in the orthorhombic system with a = = 1.0125(2), b = 1.2439(1) and c = 0.9304(3) nm, Z = 4 in space group P212121• The compound is isostructural with the analogous chloro derivative. The crystal structure has been refined from diffractometer data to conventional R and Ra values of 0.045 and 0.048 for 2277 reflections with I ~ 2a (I). The heterocyclic four-membered ring has a puckering angle of 8.9(4) 0 • The dihedral angle between the best planes of the /)-propiothiolactone and benzene rings is 84.1(2) 0 • The structure consists of discrete molecules connected along the a axis by intermolecular hydrogen bonds N-H ... O of 291.9(7) pm

Synthesis and Spectroscopic Evidences of N-Arylmaleimides and N-Aryl-2,3-dimethylmaleimides

A series of N-arylmaleimides (N-aryl-MI) and N-aryl-2,3-dimethylmaleimides (N-aryl-DiMeMI) were prepared by condensation of primary amines with maleic anhydride (MAn) and 2,3-dimethylmaleic anhydride (DiMeMAn), respectively. Preparation of N-aryl-MI proceeded through the formation of N-arylmaleamic acid, which subsequently cyclized to N-aryl-MI. In the reaction of N-arylamines with DiMeMAn, cyclic condensation products were formed in one step. By means of one- and two-dimensional 1H and 13C NMR spectroscopy it was proven that Naryl- DiMeMI and not isomaleimides were formed by a one step reaction

Crystal and Molecular Structures of N-Phenylmaleimide and N-Phenyl-2,3-dimethylmaleimide

N-Phenylmaleimide and N-phenyl-2,3-dimethylmaleimide have been synthesized and structurally characterized by X-ray diffraction. The crystal structure of the second compound proves that condensation of PhNH2 with 2,3-dimethylmaleic anhydride gives, through a one step mechanism, N-phenyl-2,3-dimethylmaleimide and not the corresponding isomaleimide

The influence of the chemical structure on the properties of molecularly imprinted crosslinked polymers

U radu je opisana sinteza monomera N-metakril-N,N\u27-dicikloheksiluree (MA-DCU) i N-metakril-N,N\u27-diizopropiluree (MA-DiPrU) te polimerizacija s etilen-glikol dimetakrilatom (EDMA). Polimerizacija je provedena u butanonu s benzoil-peroksidom (Bz2O2) do visoke konverzije. Dobiveni su umreženi kopolimeri netopljivi u organskim otapalima. Neovisno o sastavu, kopolimeri se razgrađuju dvostupnjevitim mehanizmom pri temperaturama od 180 °C do 450 °C uz izdvajanje cikloheksilizocijanata (C6H11NCO), odnosno izopropilizocijanata (C3H7NCO) pri temperaturi od 180 °C do 250 °C. Ostatak nakon izdvajanja izocijanata je termički stabilan nanoporozni umreženi kopolimer metakril-cikloheksilamida (MA-CHA), odnosno metakril-izopropilamida (MA-iPrA) s EDMA. Ti se kopolimeri razgrađuju u jednom stupnju pri temperaturama od 280 °C do 450 °C. Sintetizirani su i neporozni kopolimeri MA-CHA, odnosno MA-iPrA s EDMA (modelni kopolimeri) radi usporedbe svojstava s odgovarajućim nanoporoznim kopolimerima.The present paper describes the synthesis of monomers N-methacryl-N,N’-dicyclohexylurea (MA-DCU) and N-methacryl-N,N’-diisopropylurea (MA-DiPrU) and their polymerization with ethylene glycol dimethacrylate (EDMA). Polymerization were carried out in butanone by using dibenzoyl-peroxide (Bz2O2) up to high conversion. All prepared copolymers are insoluble in common organic solvent. Crosslinked copolymers decompose thermally at temperatures from 180 °C to 450 °C under the separation of cyclohexylisocyanate (C6H11NCO) or isopropylisocyanate (C3H7NCO) at temperature between 180 °C and 250 °C. Residues after the removal of isocyanate are thermally stable nanoporous crosslinked copolymers of methacryl-cyclohexylamide (MA-CHA) or methacryl-isopropylamide (MA-iPrA) with EDMA, which decompose by a one-step mechanism between 280 °C and 450 °C. Nonporous model copolymers of MA-CHA and MA-iPrA with EDMA were also prepared in order to compare their properties with the properties of corresponding nanoporous copolymers

Crystal and Molecular Structure of (S)-a-(pCyanobenzenesulphonamido)-B- propiothiolactone, C10H8N203S2

Crystals of the title compound are monoclinic, space group P21, with a = 1.0018(2), b = 0.9722(2), c = 0.6262(1) nm, fJ = 102.32(1)° and Z = 2. The structure was solved by direct methods using 1113 reflections with I 2\u27: 20 (I) and refined to a conventional R index of 0.051. The heterocyclic four-membered ring is bent and has a puckering angle of 18.7(7)°. The dihedral angle between the best planes of the B-propiothiolactone and benzene ring is 70.2(3)°. Discrete molecules are connected along the b axis by intermolecular hydrogen bonds N--H ... O of 309.5(9) pm