Premium
Novel O , O′ ‐Donor Oxo‐Mo IV Hydrotris(3‐isopropylpyrazolyl)borate Complexes Formed by Chelation of Potentially Hydrogen‐Bonding Phenolate Ligands on Reduction of Dioxo‐Mo VI Complexes
Author(s) -
Ng Victor W. L.,
Taylor Michelle K.,
Hill Lyndal M. R.,
White Jonathan M.,
Young Charles G.
Publication year - 2010
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201000214
Subject(s) - chemistry , octahedron , denticity , chelation , ligand (biochemistry) , hydrogen bond , stereochemistry , medicinal chemistry , octahedral molecular geometry , molecule , crystallography , crystal structure , inorganic chemistry , biochemistry , receptor , organic chemistry
The oxo‐Mo IV complexes formed in the reactions of cis ‐Tp i Pr Mo VI O 2 (OAr‐R) [Tp i Pr = hydrotris(3‐isopropylpyrazol‐1‐yl)borate, – OAr‐R = phenolate derivative] complexes with PEt 3 or PEt 2 Ph in acetonitrile depend on the nature of the potential hydrogen‐bonding group (R) incorporated into the phenolate ligand. Green, diamagnetic, oxo(phosphoryl)‐Mo IV complexes, Tp i Pr Mo IV O(OAr‐R)(OPR′ 3 ), are produced when R is absent or is a non‐coordinating group such as 2‐OMe and 3‐NEt 2 ; six‐coordinate Tp i Pr MoO(OC 6 H 4 OMe‐2)(OPEt 3 ) was structurally characterized and exhibits a distorted octahedral geometry typical of such species. When R is a carbonyl functionality, complete oxygen atom transfer leads to green or purple, diamagnetic, chelate complexes of the type, Tp i Pr Mo IV O(OAr‐R‐κ 2 O , O′ ). The R = 2‐COEt, 2‐CO 2 Me and 2‐CO 2 Ph derivatives exhibit six‐coordinate, distorted‐octahedral structures possessing fac Tp i Pr , terminal oxo and bidentate O , O′ ‐donor – OAr‐R ligands. Where R is an amido functionality, CONHPh, the complexes, Tp i Pr Mo IV O(OC 6 H 4 CONHPh‐2‐κ 2 O , O′ ) · OPR′ 3 (R′ 3 = Et 3 , Et 2 Ph), are isolated. Here, the six‐coordinate, distorted‐octahedral complex forms an intermolecular NH ··· OPR′ 3 hydrogen bond to the lattice OPR′ 3 molecule. Thus, facile chelation of potential hydrogen‐bonding phenolate ligands suppresses hydrogen‐bond‐stabilized aquation or hydroxylation cis to the oxo group in these Mo IV complexes.