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Silyl Cations Stabilized by Pincer Type Ligands with Adjustable Donor Atoms
Author(s) -
Denhof Andreas,
Olaru Marian,
Lork Enno,
Mebs Stefan,
Chęcińska Lilianna,
Beckmann Jens
Publication year - 2020
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.202000800
Subject(s) - chemistry , silylation , counterion , pincer movement , medicinal chemistry , stereochemistry , ion , catalysis , organic chemistry
Novel E,C,E'‐pincer supported silyl cations (E, E' = O, S, Se, Au) were prepared in three steps starting from 2,6‐F 2 C 6 H 3 SiMe 2 H ( 1a ) and 2,6‐Br 2 C 6 H 3 SiMe 2 H ( 1b ), which were first converted in two complementary ways into 2,6‐(Ph 2 P) 2 C 6 H 3 SiMe 2 H ( 2 ). The oxidation of 2 with H 2 O 2 · urea, S 8 , and Se 8 afforded 2,6‐(Ph 2 PE) 2 C 6 H 3 SiMe 2 H ( 3a , E = O; 3b , E = S; 3c , E = Se) and 2‐(Ph 2 PE)‐6‐(Ph 2 P)‐C 6 H 3 SiMe 2 H ( 4b , E = S; 4c , E = Se), which were reacted to the E,C,E‐supported silyl cations [2,6‐(Ph 2 PE) 2 C 6 H 3 SiMe 2 ] + ( 5a , E = O, counterion Br 3 – ; 5b , E = S, counterion B(C 6 F 5 ) 4 – ; 5c , E = Se, counterion B(C 6 F 5 ) 4 – ), the E,C‐supported silyl cations [2‐(Ph 2 PE)‐6‐(Ph 2 P)C 6 H 3 SiMe 2 ] + ( 6b , E = S, not isolated; 6c , E = Se, not isolated), the O,C,S‐supported silyl cation [2‐(Ph 2 PS)‐6‐(Ph 2 PO)C 6 H 3 SiMe 2 ] + ( 7 , counterion B(C 6 F 5 ) 4 – ) as well as the E,C,Au‐supported silyl cations [2‐(Ph 2 PAuC 6 F 5 )‐6‐(Ph 2 PE)C 6 H 3 SiMe 2 ] + ( 8b , E = S, counterion [B{3,5‐(CF 3 ) 2 C 6 H 3 } 4 ] – ; 8c , E = Se, [B{3,5‐(CF 3 ) 2 C 6 H 3 } 4 ] – ) using Br 2 , O 2 , S 8 , (tht)AuC 6 F 5 , Ph 3 C[B(C 6 F 5 ) 4 ] and Ph 3 C[B{3,5‐(CF 3 ) 2 C 6 H 3 } 4 ]. All compounds were characterized by multinuclear ( 1 H, 13 C, 19 F, 29 Si, 31 P, 77 Se) NMR spectroscopy, ESI MS spectrometry and X‐ray crystallography ( 2 , 3a· H 2 O, 3b , 3c , 4b , 5a , 5c , 7 , 8b , 8c ). The gas phase structures of 2 , 3a–c , 5a–c (fully optimized) and 8b , 8c (single‐point calculations) were studied at the B3PW91/6‐311+G(2df,p) level of theory. A set of real‐space bonding indicators (RSBIs) derived from the theoretically calculated electron and pair densities were analyzed utilizing the atoms‐in molecules (AIM) and electron‐localizability indicator (ELI‐D) space partitioning schemes.