Syntheses of Group 5 Amide Amidinates and Their Reactions with Water: Different Reactivities of Nb(V) and Ta(V) Complexes.

Chemistries of Nb(V) and Ta(V) compounds are essentially identical as a result of lanthanide contraction. Hydrolysis of M(NMe) (M = Nb, Ta), for example, yields [M(μ-O)(NMe)] (M = Nb, ; Ta, ) reported earlier. The similar reactivities of Nb(V) and Ta(V) compounds make it challenging, for example, to separate the two metals from their minerals.

Spin-phonon couplings in transition metal complexes with slow magnetic relaxation.

Spin-phonon coupling plays an important role in single-molecule magnets and molecular qubits. However, there have been few detailed studies of its nature. Here, we show for the first time distinct couplings of g phonons of Co(acac)(HO) (acac = acetylacetonate) and its deuterated analogs with zero-field-split, excited magnetic/spin levels (Kramers doublet (KD)) of the S = 3/2 electronic ground state.

Product in indole detection by Ehrlich's reagent.

Ehrlich's reagent (p-dimethylaminobenzaldehyde [DMAB, 1] in 95% EtOH with HCl as catalyst) was employed in spot tests of indoles, providing a diagnosis of, for example, liver diseases, hemolytic processes, occlusion of the common bile duct, and carcinoid syndrome. Although the reagent has been widely used for more than a century, it is not clear how many indole molecules react with a DMAB molecule and whether the reaction takes place at the α- or β-position of the indole molecule. Research here shows that the reaction of DMAB (1) with indole (2) in a 1:2 ratio gives β-bis(indolyl)methane (3).

Reactions of zirconium amide amidinates with dioxygen. Observation of an unusual peroxo intermediate in the formation of oxo compounds.

Reaction of d(0) Zr(NMe2)2[MeC(N(i)Pr)2]2 (1) with O2 at -30 °C gives three Zr containing products: a peroxo trimer {(μ-η(2):η(2)-O2)Zr[MeC(N(i)Pr)2]2}3 (2), an oxo dimer {(μ-O)Zr[MeC(N(i)Pr)2]2}2 (3), and an oxo polymer {(μ-O)Zr[MeC(N(i)Pr)2]2}n (4). is a rarely observed peroxo complex from the reaction of a d(0) complex with O2.

Reactions of Group 4 amide guanidinates with dioxygen or water. Studies of the formation of oxo products.

Reactions of the zirconium amide guanidinates (R2N)2M[(i)PrNC(NR2)N(i)Pr]2 (R = Me, M = Zr, 1; M = Hf, 2; R = Et, M = Zr, 3) with O2 or H2O give products that are consistent with the oxo dimers {M(μ-O)[(i)PrNC(NR2)N(i)Pr]2}2 (R = Me, M = Zr, 4; M = Hf, 5; R = Et, M = Zr, 6) and polymers {M(μ-O)[(i)PrNC(NR2)N(i)Pr]2}n (R = Me, M = Zr, 7; M = Hf, 8; R = Et, M = Zr, 9). Mass spectrometric (MS) analyses of the reactions of water in air with 1 and 2 show formation of the Zr monomer Zr(═O)[(i)PrNC(NMe2)N(i)Pr]2 (10), oxo dimers 4 and 5, and dihydroxyl complexes M(OH)2[(i)PrNC(NMe2)N(i)Pr]2 (M = Zr, 11; Hf, 12). Similar MS analyses of the reaction of diethylamide guanidinate 3 with water in air show the formation of Zr(═O)[(i)PrNC(NEt2)N(i)Pr]2 (13), Zr(OH)2[(i)PrNC(NEt2)N(i)Pr]2 (14), 6, and {(Et2N)Zr[(i)PrNC(NEt2)N(i)Pr]2}(+) (15).