Severity: Warning
Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 143
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 143
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 209
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 994
Function: getPubMedXML
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3134
Function: GetPubMedArticleOutput_2016
File: /var/www/html/application/controllers/Detail.php
Line: 574
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 488
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
Macrocycles that assemble into nanotubes exhibit emergent properties stemming from their low dimensionality, structural regularity, and distinct interior environments. We report a versatile strategy to synthesize diverse nanotube structures in a single, efficient reaction by using a conserved building block bearing a pyridine ring. Imine condensation of a 2,4,6-triphenylpyridine-based diamine with various aromatic dialdehydes yields chemically distinct pentagonal [5 + 5], hexagonal [3 + 3], and diamond-shaped [2 + 2] macrocycles depending on the substitution pattern of the aromatic dialdehyde monomer. Atomic force microscopy and X-ray diffraction demonstrate that protonation of the macrocycles under the mild conditions used for their synthesis drives assembly into high-aspect ratio nanotubes. Each of the pyridine-containing nanotube assemblies exhibited measurable proton conductivity by electrochemical impedance spectroscopy, with values as high as 10 S m (90% R.H., 25 °C) that we attribute to differences in their internal pore sizes. This synthetic strategy represents a general method to access robust nanotube assemblies from a universal pyridine-containing monomer, which will enable systematic investigations of their emergent properties.
Download full-text PDF |
Source |
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http://dx.doi.org/10.1021/jacs.1c02789 | DOI Listing |
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