PMID- 34264674
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20210729
LR  - 20210729
IS  - 1948-7185 (Electronic)
IS  - 1948-7185 (Linking)
VI  - 12
IP  - 29
DP  - 2021 Jul 29
TI  - (15)N Solid-State NMR as Bright Eyes to See the Isomerization of the Azo Bond: 
      Revision of Tris(beta-hydroxyl-azo)-benzene to Tris(beta-keto-hydrazo)-cyclohexane in 
      Porous Organic Polymers.
PG  - 6767-6772
LID - 10.1021/acs.jpclett.1c01750 [doi]
AB  - Porous organic polymers (POPs) have aroused great and wide attention from the 
      materials community, while the identification of their precise structures is 
      still very challenging. The well-defined structures are of great importance in 
      understanding the relationship between the structure and function of the polymer 
      materials, though they are sometimes ignored and do not receive enough attention. 
      In this letter, an efficient (15)N labeling technique and (15)N solid-state NMR 
      ((15)N-SSNMR) were combined to obtain strong evidence for the presence of the azo 
      bond and keto-hydrazone structure in the solid state. Thus, the structure of 
      tris(beta-hydroxyl-azo)-benzene in previously proposed hydroxylazobenzene polymers 
      was revised to tris(beta-keto-hydrazo)-cyclohexane in TKH-POPs for the first time. 
      In contrast, similar tautomerization did not occur in the azo coupling 
      polymerization of 1,3,5-triaminobenzene and diazonium salts, i.e., 
      tris(beta-amino-azo)-benzene remained in Azo-POPs. This work will open up a window 
      to develop innovative porous organic polymers more efficiently with the aid of 
      (15)N-SSNMR.
FAU - Luo, Xian-Sheng
AU  - Luo XS
AD  - School of Materials Science and Engineering, Experimental Center for Advanced 
      Materials, Beijing Institute of Technology, Beijing 100081, China.
FAU - Deng, Han-Lin
AU  - Deng HL
AD  - School of Materials Science and Engineering, Experimental Center for Advanced 
      Materials, Beijing Institute of Technology, Beijing 100081, China.
FAU - Chi, Shumeng
AU  - Chi S
AD  - School of Materials Science and Engineering, Experimental Center for Advanced 
      Materials, Beijing Institute of Technology, Beijing 100081, China.
FAU - Liu, Yan
AU  - Liu Y
AD  - School of Materials Science and Engineering, Experimental Center for Advanced 
      Materials, Beijing Institute of Technology, Beijing 100081, China.
FAU - Huang, Mu-Hua
AU  - Huang MH
AUID- ORCID: 0000-0002-3563-7381
AD  - School of Materials Science and Engineering, Experimental Center for Advanced 
      Materials, Beijing Institute of Technology, Beijing 100081, China.
LA  - eng
PT  - Journal Article
DEP - 20210715
PL  - United States
TA  - J Phys Chem Lett
JT  - The journal of physical chemistry letters
JID - 101526034
SB  - IM
EDAT- 2021/07/16 06:00
MHDA- 2021/07/16 06:01
CRDT- 2021/07/15 17:21
PHST- 2021/07/16 06:00 [pubmed]
PHST- 2021/07/16 06:01 [medline]
PHST- 2021/07/15 17:21 [entrez]
AID - 10.1021/acs.jpclett.1c01750 [doi]
PST - ppublish
SO  - J Phys Chem Lett. 2021 Jul 29;12(29):6767-6772. doi: 10.1021/acs.jpclett.1c01750. 
      Epub 2021 Jul 15.