New examples of –C–F–Ae (Ae = alkaline earth) and –C–F–K bonding†
Journal Publication ResearchOnline@JCUAbstract
From redox transmetallation/protolysis reactions of alkaline earth metals, Mg, Ca, and Sr with bispenta- fluorophenylmercury and N,N0-bis(2-trifluoromethylphenyl)formamidine (CF3FormH) in tetrahydrofuran (thf), the complexes [Ae(CF3Form)2(thf)2] (Ae = Mg 1, Ca 2) and [Sr(CF3 Form)2 ] 3 have been isolated. Reaction of 3 with 18-crown-6 yielded the charge separated [Sr(CF3Form)(18-crown-6)(thf)][Sr(CF3- Form)3] 3a, and from heating 3 in C6 D 6, crystals of [Sr4 (CF3 Form)4 L4 ] (L = oxidomethyl(2-trifluoro- methyl)phenylamide) 3b were obtained. The crude product 4 from a synthesis with Ba similar to those of 1–3 yielded the large cage [Ba19 (CF3 Form)6 L6 F26 (diglyme)6] 4a. Complexes 1 and 2 are monomeric with chelating CF3Form ligands, six coordination of the Ae metal, and cis and trans thf ligands respectively. In 3, trans chelating CF3Form ligands are supported by –CF3–Sr coordination. Charge-separated 3a, has a nine-coordinate cation, whilst the unique nine-coordinate tris(formamidinato)strontiate( II) anion has three –CF3–Sr interactions. In the cage 3b, each Sr atom is nine coordinate with chelating CF3Form and 2-CF3C 6H 4NCHO– ligands, two bridging oxygens from the latter ligands, and three –CF3–Sr interactions. The Ba19 cage 4a has a central BaF8 unit, which is linked by bridging fluorides to three different Ba atoms, which also have CF 3–Ba bonds. The complexes [K 2(CF3Form)2(dme)]N 5 and [K3(CF3Form)3]N 6a were obtained by deprotonation of CF3FormH with K(N(SiMe3 )2) and KH respectively, and a similar treatment of N-(2,6-difluorophenyl)acetamide with the silylamide gave potassium N-acetyl-N-(2,6- difluorophenyl)amide 7. Complexes 5 and 6a are 1-D polymers with two and three differently coordinating CF3Form ligands respectively. The structures are based on chelating bridging CF3Form ligands supported by –CF 3–A bonding including rare chelating CF3 groups. 7 forms a 2-D polymer sheet, based on tridentate FNO ligands.
Journal
New Journal of Chemistry
Publication Name
New Journal of Chemistry
Volume
49
ISBN/ISSN
1369-9261
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Pages Count
10
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Publisher
Royal Society of Chemistry
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EISSN
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DOI
10.1039/d5nj03383g