Jean-Pierre Charland

Structure of an unusual 5:2 methylmercury: adenine complex

The [(CH 3 Hg) 5 Ad 2 ](NO 3 )3·3H 2 O compound is monoclinic, P 2 1 / c , a = 10.717(7), b = 26.680(8), c = 11.778(2) A, β= 102.59(4)°, Z =4. The structure was solved on 2841 observed reflections to R = 0.045. The crystal contains an equal number of N7, N9-bonded [(CH 3 Hg) 2 Ad] + ions and N3,N7,N9- bonded [(CH 3 Hg) 3 Ad] 2+ ions joined into dimers via pairs of complementary N6H⋯1 hydrogen bonds. The [(CH 3 Hg) 3 Ad] 2+ ion is also found in crystals of [(CH 3 Hg) 3 Ad] (NO 3 ) 2 ·H 2 0: triclinic, P , a = 7.017(3), b = 11.345(6), c = 12.722(3) A, α= 64.91(3), β = 87.50(3), γ= 89.59(4)°, Z = 2, R = 0.057, 1960 observed reflections. The 1 H and 13 C NMR spectra of the 5:2 complex in DMSO-d 6 contain only one set of proton signals for the adenine ring and the CH 3 Hg + ions. This indicates that the complexes exchange their stoichiometries rapidly on the NMR time scale. In addition, the CH 3 Hg + cations are shuffled among the five unequivalent coordination sites.

Infrared spectra of silver complexes with 2-aminopyridine and crystal structure of the 4:3 aminopyridine-silver nitrate compound

The 4∶3 complex formed between 2-aminopyridine (ampy) and AgNO3 belongs to the orthorhombic space groupPccn. The unit cell of dimensionsa=7.992(4),b=16.788(5),c=21.034(8) Å contains four formula units. The structure was refined on 998 nonzero reflections toR=0.038. The crystal contains the dimeric [Ag3(ampy)4]3+ cation. Two of the three independent Ag atoms are each coordinated to two ampy ligandsvia the heterocyclic nitrogen lone pair (mean Ag-N=2.18 Å), and the N-Ag-N angle in this [ampy-Ag-ampy]+ unit is 154.0°. By using the two available amino groups, the [ampy-Ag-ampy]+ unit acts as a bidentate “ligand,” and two such units related by a twofold axis achieve a roughly tetrahedral environment of NH2 lone pairs about the third Ag atom (mean Ag-N=2.39 Å). The infrared spectra of [Ag3(ampy)4](NO3)3, [Ag(ampy)2]ClO4, [Ag3(ampy-H)2]NO3, and [Ag3(ampy-H)2]ClO4, and those of their amino-deuterated derivatives, are discussed. Diagnostic regions are proposed to identify coordinationvia the amino group and the heterocyclic nitrogen atom.

A metal complex of 2,4,6-tris(N,N-di-isopropylamino)cyclotriphosphoxane that is an intermediate to the P4O4M2 cage complex

Reaction of (Pri2N)2P(O)H with Mo(CO)6 gives the title compound (2) identified as a Mo(CO)5 complex of the six-membered [Pri2NPO]3 heterocycle and found to be an intermediate for the formation of the P4O4M2 cage complex.