Second sphere coordination in fluoroanion binding: Synthesis, spectroscopic and X-ray structural study of [Co(phen)2CO3](Pfbz)·6H2O

Binding of fluorine containing anions by new cationic Co(III) complex: Competitive interaction of chloride and hexafluorophosphate with [Co(phen)(H2biim)2]3+

“…The PF 6 À anions possess nearly equal P-F distances ranging from 1.553(4) to 1.593(4) Å , and the geometry around each P atom is almost perfectly octahedral. The Co-N(phen), Co-N(H 2 biim), P-F bond lengths and N-Co-N, F-P-P bond angles are in good agreement with those reported in literature [25,[28][29][30]51,52]. Selected bond lengths and angles are reported in Table 1.…”

“…Literature survey revealed that organic and organometallic based anion receptors have been extensively studied as compared to metal based anion receptors [14][15][16][17][18][19][20][21][22][23][24]. Thus, in continuation of our research program to exploit cobalt(III) complexes as anion receptors (complexants) [25][26][27][28][29][30], we have synthesized a new mixed ligand cationic complex [Co(phen)(H 2 biim) 2 ] 3+ as its chloride salt. The complex cation possesses all the characteristic features [31] of good binding agent: (i) three unit positive charge for effective electrostatic interactions, (ii) hydrogen bond donor groups (C-H and N-H) and (iii) a stable framework onto which these structural components can be assembled.…”

The relevance of the fluorine interactions in the supramolecular structure of a complex constructed from copper(II) hexafluoroacetylacetonate and the 4′-(3-pyridyl)-2,2′:6′,2″-terpyridine ligand. Novel C–F/π synthons involving the π-system of the terpyridine moieties and those of the hexafluoroacetylacetonate chelate rings

“…The only component of the intra-ion group, C126-H12AÁ Á ÁF15B, is located in the cationic trinuclear portion, connecting an outer pyridyl ring of a chelating terpy fragment bonded to Cu2 with a F atom from a hfacac moiety bonded to the central Cu1. The geometric parameters (Table 3, first entry) are close to the range of those observed in the ionic compound [Co(phen) 2 CO 3 ](Pfbz)Á6H 2 O (Pfbz = pentafluorobenzoato) (ranges: HÁ Á ÁF: 2.538-2.662 Å ; CÁ Á ÁF: 3.171-3.501 Å ; C-HÁ Á ÁF: 125.7-150.28) [30], where it is stated that these type of weak interactions can be discernible despite being ionic species.…”

Weak C-H…F-C interactions in carboxylate anion binding: Synthesis, spectroscopic and X-ray structural studies of [Co(phen)2CO3]2 (C7H3O2FCl)Cl·11H2O and [Co(phen)2CO3](C7H3NO4Cl)·6H2O

“…17 In this backdrop it is worth mentioning that we have undertaken an extensive research programme to exploit cationic cobalt(III) complex, [Co(phen) 2 CO 3 ] + as anion receptors. [18][19][20][21][22] and the detailed packing analyses of the complexes formed by this cation show that the role of the oxygen atoms of the carbonato group (hydrogen bond acceptor) and the hydrogen atom of the 1,10-phenanthroline moiety (C-H donor) is complementary towards lattice stabilization. Considering such a cohesive behaviour, our recent investigation on [Co(phen) 2 CO 3 ] (pentafluorobenzoate)⋅6H 2 O 22 clearly demonstrated that other than the individual strength of C-H⋅⋅⋅F interactions, their cooperative contribution is substantial in lattice stabilization.…”

“…[23][24][25][26][27][28][29][30][31] At this stage, a careful choice of the counter anion becomes essential as we are trying to evaluate molecular events that differ at an energy level less than or equal to 1-2 kcal/mol. The choice of a cation was readily met with [Co(phen) 2 CO 3 ] + from our previous experience [18][19][20][21][22] and consideration of the topological features and charge distribution led to the carboxylate anions; 2-chloro-5-fluorobenzoate (cfbz) and 2-chloro-5-nitrobenzoate (cnbz).…”