title: Effect of Ancillary Ligand on Electronic Structure as Probed by51V Solid-State NMR Spectroscopy for Vanadium-o-Dioxolene Complexes.
abstract: A series of vanadium(V) complexes with o-dioxolene (catecholato) ligands and an ancillary ligand, (N-(salicylideneaminato)ethylenediamine) (hensal), were investigated using51V solid-state magic angle spinning NMR spectroscopy (51V MAS NMR) to assess the local environment of the vanadium(V). The solid-state51V NMR parameters of vanadium(V) complexes with a related potentially tetradentate ancillary ligand (N-salicylidene-N'-(2-hydroxyethyl)ethylenediamine) (h2shed) were previously shown to be associated with the size of the HOMO-LUMO gap in the complex, and as such provide insights on the interaction between metal ion and ligand (P. B. Chatterjee, et al.,Inorg. Chem50 (2011) 9794). Our results show that the modification of the ancillary ligand does not impact the observed trend between complexes ranging from catechols with electron rich to electron poor substituents. However, the ancillary ligand does impact the size of the HOMO-LUMO separation in the parent complex and thus the solid-state vanadium NMR chemical shift of the unsubstituted vanadium complex. For these complexes significant changes observed in the isotropic shifts and more modest changes detected in theCQreflect the electronic changes in the complex as the catechol is varied. However, no obvious trend was observed in the chemical shift anisotropies (δσand ησ) with the variation in the catechol. The electronic changes in the coordination environment of the vanadium can be described using solid-state51V NMR spectroscopy.
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968.
authors.forename: Olga
authors.initials: O
authors.lastname: Goncharova-Zapata
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA. Tel. +1-970-491-7635.
authors.forename: Pabitra B
authors.initials: PB
authors.lastname: Chatterjee
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968.
authors.forename: Guangjin
authors.initials: G
authors.lastname: Hou
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968.
authors.forename: Laurence L
authors.initials: LL
authors.lastname: Quinn
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968.
authors.forename: Mingyue
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968.
authors.forename: Jenna
authors.initials: J
authors.lastname: Yehl
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968.
authors.forename: Debbie C
authors.initials: DC
authors.lastname: Crans
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968.
authors.forename: Tatyana
authors.initials: T
authors.lastname: Polenova