{"id":{"repo_id":"texas-state","oai_identifier":"oai:digital.library.txst.edu:10877/14768"},"canonical_url":"https://search.dev.ndltd.org/etd/texas-state/oai:digital.library.txst.edu:10877/14768","repository":{"repo_id":"texas-state","name":"Texas State University","base_url":"https://digital.library.txst.edu/server/oai/request"},"display":{"title":"Synthesis and cation binding properties of bis-bridged calix[6]arenes","abstract":"Calixarenes have been studied and utilized for their molecular recognition properties. A total of four bis-bridged calix[6]arenes have been synthesized and their metal binding properties and structural conformations were studied in solid, solution, and gas phase. Methods of testing include: NMR titrations, liquid-liquid extractions, x-ray crystallography, and electrospray ionization-MS. A dialkylated calix[6]arene was used as the principle starting material which predisposed the four remaining phenolic hydroxyl groups for placement of two bis-electrophiles. The bis-electrophiles were triethylene glycol di-p-tosylate, α,α-di-bromomethyl-m-xylene, and 2,6-bis(bromomethyl) pyridine. All of the compounds tested, with the exception of the bis-xylenyl, formed 1:1 complexes. The bis-xylenyl calix[6]arene is a poor cation binder that is conformationally mobile at room temperature. In contrast the bis-pyridinyl calix[6]arene was a non-selective strong binder of all alkali metal ions. Both bis-bridged aromatic compounds were in a 1,2,3-alternate conformation. Also synthesized were bis-crown-4-calix[6]arene in the cone and 1,2,3-alternate conformation. The calixcrown conformers were selective for the larger alkali metals, cesium and rubidium, with the Cs+/Na+ selectivity of the cone being 1,400 and that of the 1,2,3-alternate being 144, in solution. Similar results were observed in gas phase competition studies where both conformers exhibited exclusive Cs+ selectivity over Rb+ and a selectivity trend for consecutive larger cations in competition mixtures of Na+/K+, and K+/Rb+.","abstract_html":"Calixarenes have been studied and utilized for their molecular recognition properties. A total of four bis-bridged calix[6]arenes have been synthesized and their metal binding properties and structural conformations were studied in solid, solution, and gas phase. Methods of testing include: NMR titrations, liquid-liquid extractions, x-ray crystallography, and electrospray ionization-MS. A dialkylated calix[6]arene was used as the principle starting material which predisposed the four remaining phenolic hydroxyl groups for placement of two bis-electrophiles. The bis-electrophiles were triethylene glycol di-p-tosylate, α,α-di-bromomethyl-m-xylene, and 2,6-bis(bromomethyl) pyridine. All of the compounds tested, with the exception of the bis-xylenyl, formed 1:1 complexes. The bis-xylenyl calix[6]arene is a poor cation binder that is conformationally mobile at room temperature. In contrast the bis-pyridinyl calix[6]arene was a non-selective strong binder of all alkali metal ions. Both bis-bridged aromatic compounds were in a 1,2,3-alternate conformation. Also synthesized were bis-crown-4-calix[6]arene in the cone and 1,2,3-alternate conformation. The calixcrown conformers were selective for the larger alkali metals, cesium and rubidium, with the Cs+/Na+ selectivity of the cone being 1,400 and that of the 1,2,3-alternate being 144, in solution. Similar results were observed in gas phase competition studies where both conformers exhibited exclusive Cs+ selectivity over Rb+ and a selectivity trend for consecutive larger cations in competition mixtures of Na+/K+, and K+/Rb+.","abstract_has_math":false,"creators":["Farmer, Dustin Blaine"],"institution":"Southwest Texas State University","degree_name":"Master of Science","degree_level":"Masters","degree_discipline":"Biochemistry","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1999,"date_issued":"1999-12","date_published":"1999-12","updated_at":"2026-07-27T21:22:32Z","subjects":["calixarenes","synthesis","calix[6]arenes","gas phase","binding properties"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/10877/14768","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Farmer, Dustin Blaine"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2021-11-03T13:51:35Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2021-11-03T13:51:35Z"]},{"key":"dc:date.issued","label":"Date","values":["1999-12"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biochemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Southwest Texas State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["calixarenes","synthesis","calix[6]arenes","gas phase","binding properties"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10877/14768"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Calixarenes have been studied and utilized for their molecular recognition properties. A total of four bis-bridged calix[6]arenes have been synthesized and their metal binding properties and structural conformations were studied in solid, solution, and gas phase. Methods of testing include: NMR titrations, liquid-liquid extractions, x-ray crystallography, and electrospray ionization-MS. A dialkylated calix[6]arene was used as the principle starting material which predisposed the four remaining phenolic hydroxyl groups for placement of two bis-electrophiles. The bis-electrophiles were triethylene glycol di-p-tosylate, α,α-di-bromomethyl-m-xylene, and 2,6-bis(bromomethyl) pyridine. All of the compounds tested, with the exception of the bis-xylenyl, formed 1:1 complexes. The bis-xylenyl calix[6]arene is a poor cation binder that is conformationally mobile at room temperature. In contrast the bis-pyridinyl calix[6]arene was a non-selective strong binder of all alkali metal ions. Both bis-bridged aromatic compounds were in a 1,2,3-alternate conformation. Also synthesized were bis-crown-4-calix[6]arene in the cone and 1,2,3-alternate conformation. The calixcrown conformers were selective for the larger alkali metals, cesium and rubidium, with the Cs+/Na+ selectivity of the cone being 1,400 and that of the 1,2,3-alternate being 144, in solution. Similar results were observed in gas phase competition studies where both conformers exhibited exclusive Cs+ selectivity over Rb+ and a selectivity trend for consecutive larger cations in competition mixtures of Na+/K+, and K+/Rb+."]},{"key":"dc:format","label":"Dc Format","values":["Text"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["1 file (.pdf)"]},{"key":"dc:title","label":"Title","values":["Synthesis and cation binding properties of bis-bridged calix[6]arenes"]}]}],"canonical_facts":{"dc:creator":["Farmer, Dustin Blaine"],"dc:date.accessioned":["2021-11-03T13:51:35Z"],"dc:date.available":["2021-11-03T13:51:35Z"],"dc:date.issued":["1999-12"],"dc:description.abstract":["Calixarenes have been studied and utilized for their molecular recognition properties. A total of four bis-bridged calix[6]arenes have been synthesized and their metal binding properties and structural conformations were studied in solid, solution, and gas phase. Methods of testing include: NMR titrations, liquid-liquid extractions, x-ray crystallography, and electrospray ionization-MS. A dialkylated calix[6]arene was used as the principle starting material which predisposed the four remaining phenolic hydroxyl groups for placement of two bis-electrophiles. The bis-electrophiles were triethylene glycol di-p-tosylate, α,α-di-bromomethyl-m-xylene, and 2,6-bis(bromomethyl) pyridine. All of the compounds tested, with the exception of the bis-xylenyl, formed 1:1 complexes. The bis-xylenyl calix[6]arene is a poor cation binder that is conformationally mobile at room temperature. In contrast the bis-pyridinyl calix[6]arene was a non-selective strong binder of all alkali metal ions. Both bis-bridged aromatic compounds were in a 1,2,3-alternate conformation. Also synthesized were bis-crown-4-calix[6]arene in the cone and 1,2,3-alternate conformation. The calixcrown conformers were selective for the larger alkali metals, cesium and rubidium, with the Cs+/Na+ selectivity of the cone being 1,400 and that of the 1,2,3-alternate being 144, in solution. Similar results were observed in gas phase competition studies where both conformers exhibited exclusive Cs+ selectivity over Rb+ and a selectivity trend for consecutive larger cations in competition mixtures of Na+/K+, and K+/Rb+."],"dc:format":["Text"],"dc:format.medium":["1 file (.pdf)"],"dc:identifier.uri":["https://hdl.handle.net/10877/14768"],"dc:language.iso":["en"],"dc:subject":["calixarenes","synthesis","calix[6]arenes","gas phase","binding properties"],"dc:title":["Synthesis and cation binding properties of bis-bridged calix[6]arenes"],"dc:type":["Thesis"],"thesis:degree_discipline":["Biochemistry"],"thesis:degree_level":["Masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Southwest Texas State University"]},"updated_at":"2026-07-27T21:22:32Z"}