Varying the secondary coordination sphere: synthesis of cobalt and iron complexes of a tripodal ligand featuring two hydrogen-bond donors or acceptors

A CoII-Hydroxide Complex That Converts Directly to a CoII-Acetamide during Catalytic Nitrile Hydration

“…The monodentate binding mode was previously observed in the analogous [Fe II (OAc)­(L Ph )] 2– and [Zn II (OAc)­(L Ph )] 2– complexes reported by Lacy et al; however, this contrasts to the bidentate mode observed in [Ni II (OAc)­(L Ph )] 2– . An apical coordination of a hydroxide O-atom was observed in the structure of 1­(OH) (Co–O = 1.94(7) Å), falling within the range of reported Co–OH complexes with similar coordination modes. ,− A CCDC search of Co–OH complexes containing four N-donors resulted in 14 hits, where the average Co–O distance was 1.97(8) Å (Figure S5). We concluded that 1­(OH) was a hydroxide complex and not an aqua adduct (supported by the fact that two + [NMe 4 ] cations were observed for each [Co II (OH)­(L Ph )] unit).…”

“… 18 An apical coordination of a hydroxide O-atom was observed in the structure of 1(OH) (Co–O = 1.94(7) Å), falling within the range of reported Co–OH complexes with similar coordination modes. 16 , 19 − 24 A CCDC search of Co–OH complexes containing four N-donors resulted in 14 hits, where the average Co–O distance was 1.97(8) Å ( Figure S5 ). 25 We concluded that 1(OH) was a hydroxide complex and not an aqua adduct (supported by the fact that two + [NMe 4 ] cations were observed for each [Co II (OH)(L Ph )] unit).…”

A guide to secondary coordination sphere editing

“…For each of these transformations a hydrogen-bonded {[Fe III ]-O} compound was produced (Scheme 21, top). Other derivatives of this ligand have also been prepared including pyridyl 58 and tripyridyl 59 analogues (Scheme 21, bottom). For the latter (Scheme 21, bottom middle), a complete thermochemical analysis was performed, likening the activity of an isolated {[Fe III ]-O} compound to related iron enzymes that facilitate oxidative C-H hydroxylation reactions.…”

Iminopyrrole‐Based Self‐Assembly: A Route to Intrinsically Flexible Molecular Links and Knots

“…Although representing the same species, they formally differ in incorporating an N‐protonated iminopyrrole moiety ( 7‐Cd‐I ), being a coordination motif with a negative charge or a neutral amine‐azafulvene form ( 7‐Cd‐II ). The involvement of the latter was invoked to account for the IR spectra of several iminopyrrole‐originating coordination compounds [96–101] . The C pyrr‐α −C im and C im \1\2N im bond lengths analysis was performed to understand the contributions of the mesomers to the structure of the bis‐cadmium(II) catenane (Table S1, Supporting Information).…”