Synthesis and structure of samarium benzyl complex supported by bridged bis(guanidinate) ligand and its reactivity toward nitriles and phenyl isocyanate

Study of the Reactivity of the [(PE1CE2P)Ni(II)] (E1, E2 = O, S) Pincer System with Acetonitrile and Base: Formation of Cyanomethyl and Amidocrotononitrile Complexes versus Ligand Decomposition by P–S Bond Activation

“…3-Amidocrotononitrile is a rather unusual ligand for transition metal complexes; however, examples are known in which two of these ligands bind to two metal centers via the amide and nitrile nitrogen atom. − Apart from that, only one Zn complex exists, where 3-amidocrotononitrile does not act as a bridging ligand, only coordinating via the amido nitrogen to the metal center . The complexes presented herein are, to the best of our knowledge, the first examples of fully characterized metal pincer complexes, where 3-amidocrotononitrile coordinates as a monodentate ligand to a single metal center.…”

Dipolar Coupling as a Mechanism for Fine Control of Magnetic States in ErCOT-Alkyl Molecular Magnets

“…Metal–carbon bond lengths agree well with previously reported lanthanide alkyl structures. − Mononuclear 1 features the piano–stool geometry characteristic of the ErCOT moiety with the benzyl anion and THF ligands bound opposite to the COT 2– ring, giving an approximate C s symmetry. Notably, the benzyl anion is monohaptic, as while the η 1 interaction is well-known, ,,,,− lanthanide–benzyl complexes more commonly adopt an η 2 side-on interaction with the sp 2 hybridized C–CH 2 bond. ,,,,,,− The orientation of the benzyl unit can be modified by changing the cosolvent, breaking this symmetry (Figure S4). However, only the structure featured in Figure is further discussed herein.…”

Assembly of metallo-macrocycles through reductive C–C coupling of alkylnitriles by an Mg–Mg-bonded compound

“…In all of the products, the coupled amido-ene-nitrile units adopt the E conformation about the CvC bond, possibly resulting from the steric repulsion of the long alkyl chains that span above and below the macrocycle. In previous examples, however, most of the (dinuclear bridging) complexes show the Z form, and there are only several compounds that adopt the E conformation 43,48,49 The bond parameters of the bridging units in 2-4 are comparable with those in the Li, 50,51 Sr, 17 Y, 42,52 Re, 53 Sm, 54 and Yb 55 complexes with (Z)crotonitrileamido ligands, and compounds of Zr, 48 Rh 49 and Ni 43 with (E) crotonitrileamido isomer. On the basis of previous reports 17,43,52 and mechanism studies, the formation of 2-4 can be explained by a reductive α-H elimination and subsequent C-C coupling through insertion of the second nitrile, to yield possible intermediates with the imido-nitrile fragments NuCCHRC(CH 2 R)vN − .…”