Variable coordination of tris(2-pyridyl)phosphine and its oxide toward M(hfac)2: a metal-specifiable switching between the formation of mono- and bis-scorpionate complexesElectronic supplementary information (ESI) available: Copies of FT-IR, excitation and emission spectra; computation details. CCDC 1431158, 1431160, 1431159, 1033904, 1036445 and 1035512. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7dt00339k

• Main Authors: Artem'ev, Alexander V, Kashevskii, Alexey V, Bogomyakov, Artem S, Safronov, Alexander Yu, Sutyrina, Anastasiya O, Telezhkin, Anton A, Sterkhova, Irina V
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c7dt00339k

An unexpected substitution of the anionic chelating ligands at the M II centre by a neutral tripodal ligand has been observed in the reaction of Mn II , Co II , Ni II and Cu II hexafluoroacetylacetonates (hfac) with tris(2-pyridyl)phosphine (Py 3 P) or its oxide (Py 3 P = O). The nature of the metal ion in M(hfac) 2 and the M/L ratio determine the degree of substitution of hfac-anions (partial vs. total) and therefore, the structure of the complex formed (scorpionate vs. bis-scorpionate ones, respectively). Hence, the reaction of the ligands with [Cu(hfac) 2 (H 2 O) 2 ] in an equimolar ratio affords scorpionate [Cu( N , N ′, N ′′-Py 3 P = X)( O , O ′-hfac)( O -hfac)], wherein one hfac-ligand chelates metal, while the other hfac acts as an O -monodentate one. Using the two equivalents of Py 3 P in this reaction leads to [Cu( N , N ′, N ′′-Py 3 P) 2 ](hfac) 2 , which contains a bis-scorpionate cation [Cu(Py 3 P) 2 ] 2+ and two noncoordinated hfac-anions. [Co(hfac) 2 (H 2 O) 2 ] and [Ni(hfac) 2 (H 2 O) 2 ], regardless of the M/L molar ratio, react with Py 3 P = O to give cationic scorpionates [M( N , N ′, N ′′-Py 3 P = O)( O , O ′-hfac)(H 2 O)](hfac), in which one hfac-anion is noncoordinated. In contrast, [Mn(hfac) 2 (H 2 O) 2 ], on interaction with Py 3 P, results in the cationic complex [Mn( N , N ′, N ′′-Py 3 P) 2 ][Mn(hfac) 3 ] 2 bearing a bis-scorpionate cation [Mn(Py 3 P) 2 ] 2+ and two [Mn(hfac) 3 ] 2 − counterions. The synthesized scorpionates have been characterized by X-ray diffractometry, cyclic voltammetry, SQUID magnetometry, FT-IR and UV-Vis techniques. The formation of mono- and bis-scorpionate complexes has been disclosed in reaction of M(hfac) 2 with (2-Py) 3 P = X (X = none, O).