Details

Autor(en) / Beteiligte

• Mankaev, B. N.
• Zaitsev, K. V.
• Zaitseva, G. S.
• Churakov, A. V.
• Egorov, M. P.
• Karlov, S. S.

Titel

Sterically hindered tetrylenes based on new 1,10-phenanthroline-containing diols: initiators for ε-caprolactone polymerization

Ist Teil von

• Russian chemical bulletin, 2019-02, Vol.68 (2), p.380-388

Ort / Verlag

New York: Springer US

Erscheinungsjahr

2019

Quelle

SpringerLink

Beschreibungen/Notizen

• Previously unknown tetradentate ONNO-type ligands 1 – 5 (4,7-di(4-R´-phenoxy)-2,9- di(HOCR 2 CH)-1,10-phenanthrolines (R´ = Me, R–R = –(CH 2 ) 5 – ( 1 ), R = Me ( 2 ), R–R = 2,2-adamantylene ( 3 ); R´ = But, R–R = –(CH 2 ) 5 – ( 4 ), R = Me ( 5 )) were synthesized by sequential treatment of 2,9-dimethyl-4,7-di(4-R´-phenoxy)-1,10-phenanthrolines 6 (R´ = Me) and 7 (R´ = Bu t ) with excess LDA and appropriate dialkyl ketone. The structure of compound 4 was determined by single-crystal X-ray diffraction. Previously uncharacterized phenanthroline 6 was synthesized by the treatment of 4,7-dichloro-2,9-dimethyl-1,10-phenanthroline with excess p -cresol in the presence of KOH. The reaction of compounds 1 – 5 with one equivalent of Lappert´s germylene or stannylene, M[N(SiMe 3 ) 2 ] 2 (M = Ge, Sn), gave the corresponding germylenes 8 – 12 (M = Ge, R´ = Me, R–R = –(CH 2 ) 5 – ( 8 ), R = Me ( 9 ), R–R = 2,2-adamantylene ( 10 ), R´ = Bu t , R 2 = –(CH 2 ) 5 – ( 11 ), R = Me ( 12 )) and stannylenes 13 – 17 (M = Sn, R´ = Me, R–R = –(CH 2 ) 5 – ( 13 ), R = Me ( 14 ), R–R = 2,2-adamantylene ( 15 ), R´ = Bu t , R–R = –(CH 2 ) 5 – ( 16 ), R 2 = Me ( 17 )) in satisfactory yields. According to 1 H, 13 C, and 119 Sn NMR data, the synthesized stannylenes are monomeric in solution, and the tin atom has a coordination number of 4. In the series of the compounds under consideration, stannylene 16 proved to be the most active initiator for e-caprolactone polymerization, whereas the germylenes were shown to be inactive in this process.