STRUCTURES OF POTASSIUM ENCAPSULATED WITHIN THE 1,3-ALTERNATE CONFORMATION OF CALIX[4]ARENES
5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrakis(diethylcarbamoylmethoxy) calix[4]arene (L1) has been synthesised in the 1,3-alternate conformation for the first time. Proton NMR complexation studies suggest that this molecule forms 1:1 and 2:1 complexes with potassium cations. A crystal structure d...
| Auteurs principaux: | , , , , |
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| Format: | Journal article |
| Langue: | English |
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1994
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| _version_ | 1826260525213810688 |
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| author | Beer, P Drew, M Gale, P Leeson, P Ogden, M |
| author_facet | Beer, P Drew, M Gale, P Leeson, P Ogden, M |
| author_sort | Beer, P |
| collection | OXFORD |
| description | 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrakis(diethylcarbamoylmethoxy) calix[4]arene (L1) has been synthesised in the 1,3-alternate conformation for the first time. Proton NMR complexation studies suggest that this molecule forms 1:1 and 2:1 complexes with potassium cations. A crystal structure determination has been performed on the 2:1 complex [K2L1] [CuCl2] [I3], [monoclinic, space group P21/n, a = 13.972(6), b = 23.373(12), c = 25.271(12) Å, β = 102.5(1)°, Z = 4, R = 0.092 for 6501 'observed' reflections]. The structure of the 1:1 potassium complex of the related diamide, 5,11,17,23-tetra-tert-butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28- dihydroxycalix[4]arene (L2), [KL2][I3], has also been elucidated [triclinic, space group P1, a = 14.160(8), b = 16.326(10), c = 16.540(10) Å, α = 65.83(1), β = 67.37(1), γ = 88.87(1)°, Z = 2, R = 0.091 for 4976 'observed' reflections]. Remarkably, the calixarene is again found in the 1,3-alternate conformation, although 13C NMR studies suggest that, in this case, the conformation is not maintained in solution. The co-ordination spheres of the potassium cations in both structures are similar, with a hitherto unobserved combination of close contacts to four oxygen atoms, and to two phenyl rings of the respective calix[4]arenes, Molecular mechanics calculations have been carried out to investigate the relative stabilities of the calixarene conformations. |
| first_indexed | 2024-03-06T19:07:01Z |
| format | Journal article |
| id | oxford-uuid:157acf34-4989-4d28-8844-90f16c8ba833 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:07:01Z |
| publishDate | 1994 |
| record_format | dspace |
| spelling | oxford-uuid:157acf34-4989-4d28-8844-90f16c8ba8332022-03-26T10:25:46ZSTRUCTURES OF POTASSIUM ENCAPSULATED WITHIN THE 1,3-ALTERNATE CONFORMATION OF CALIX[4]ARENESJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:157acf34-4989-4d28-8844-90f16c8ba833EnglishSymplectic Elements at Oxford1994Beer, PDrew, MGale, PLeeson, POgden, M5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrakis(diethylcarbamoylmethoxy) calix[4]arene (L1) has been synthesised in the 1,3-alternate conformation for the first time. Proton NMR complexation studies suggest that this molecule forms 1:1 and 2:1 complexes with potassium cations. A crystal structure determination has been performed on the 2:1 complex [K2L1] [CuCl2] [I3], [monoclinic, space group P21/n, a = 13.972(6), b = 23.373(12), c = 25.271(12) Å, β = 102.5(1)°, Z = 4, R = 0.092 for 6501 'observed' reflections]. The structure of the 1:1 potassium complex of the related diamide, 5,11,17,23-tetra-tert-butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28- dihydroxycalix[4]arene (L2), [KL2][I3], has also been elucidated [triclinic, space group P1, a = 14.160(8), b = 16.326(10), c = 16.540(10) Å, α = 65.83(1), β = 67.37(1), γ = 88.87(1)°, Z = 2, R = 0.091 for 4976 'observed' reflections]. Remarkably, the calixarene is again found in the 1,3-alternate conformation, although 13C NMR studies suggest that, in this case, the conformation is not maintained in solution. The co-ordination spheres of the potassium cations in both structures are similar, with a hitherto unobserved combination of close contacts to four oxygen atoms, and to two phenyl rings of the respective calix[4]arenes, Molecular mechanics calculations have been carried out to investigate the relative stabilities of the calixarene conformations. |
| spellingShingle | Beer, P Drew, M Gale, P Leeson, P Ogden, M STRUCTURES OF POTASSIUM ENCAPSULATED WITHIN THE 1,3-ALTERNATE CONFORMATION OF CALIX[4]ARENES |
| title | STRUCTURES OF POTASSIUM ENCAPSULATED WITHIN THE 1,3-ALTERNATE CONFORMATION OF CALIX[4]ARENES |
| title_full | STRUCTURES OF POTASSIUM ENCAPSULATED WITHIN THE 1,3-ALTERNATE CONFORMATION OF CALIX[4]ARENES |
| title_fullStr | STRUCTURES OF POTASSIUM ENCAPSULATED WITHIN THE 1,3-ALTERNATE CONFORMATION OF CALIX[4]ARENES |
| title_full_unstemmed | STRUCTURES OF POTASSIUM ENCAPSULATED WITHIN THE 1,3-ALTERNATE CONFORMATION OF CALIX[4]ARENES |
| title_short | STRUCTURES OF POTASSIUM ENCAPSULATED WITHIN THE 1,3-ALTERNATE CONFORMATION OF CALIX[4]ARENES |
| title_sort | structures of potassium encapsulated within the 1 3 alternate conformation of calix 4 arenes |
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