1023-91-2Relevant articles and documents
Free energy and entropy changes in vertical and nonvertical triplet energy transfer processes between rigid and nonrigid molecules. A laser photolysis study
Zhang, Daisy,Closs, Gerhard L.,Chung, Dutch D.,Norris, James R.
, p. 3670 - 3673 (1993)
The free energy and entropy changes associated with intermolecular triplet energy transfer (TT) processes were determined by direct measurement of the equilibrium constant using a laser flash photolysis technique. 10,10-Dimethylanthrone and 9,9-dimethylfluorene were synthesized and used as a "rigid" donor and acceptor, respectively, in comparison with 4-methylbenzophenone, a "nonrigid" donor, and 4-methylbiphenyl, a "nonrigid" acceptor, in the TT reactions. Both the nonrigid donor and the nonrigid acceptor lose entropy while going from the twisted ground state to the planar triplet state. The ΔS values for 4-methylbenzophenone and 4-methylbiphenyl are 0.5-1.0 and 2.5-3.0 gibbs/mol, respectively.
Preparation method of 10,10-dimethylanthrone
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Paragraph 0021; 0023; 0025; 0027; 0029; 0031, (2019/06/30)
The invention belongs to the field of drug synthesis and provides a novel method of synthesizing melitracen hydrochloride intermediate 10,10-dimethylanthrone. The 10,10-dimethylanthrone is prepared from phthalic anhydride as a start material through two-step Grignard reaction and three-step closed-ring reaction. The total yield is up to 30%, and the purity of the finished intermediate is higher than 98.0%. Compared with traditional synthetic processes, the novel process herein has simple steps and greatly reduced production cost, causes little environmental pollution and helps greatly solve the environmental issue caused by the production of 10,10-dimethylanthrone.
