First Structurally Characterized Silver(I) Derivatives with Nonfluorinated β-Diketones

Abstract

Synthetic, spectroscopic, and single-crystal X-ray structural studies of diverse complexes of silver(I) acylpyrazolonate salts AgQ(R') (QH = 1-phenyl-3-methyl-4-R'(C=O)-pyrazol-5-one; Q(1), R = Ph; Q(2), R' = CF(3); Q(3), R' = Me) with neutral ligands L = unidentate PR(3) (R = Ph, o-tolyl, cyclohexyl) and Hmimt (1-methyl-2-mercaptoimidazole) and bidentate dppe (Ph(2)P(CH(2))(2)PPh(2)) and trimen (N,N,N'-trimethylethylenediamine) define the donor capability of the anionic Q(R') ligand in a variety of roles. In the free ligand Q(3)H (which crystallizes in the monoclinic space group C2/c (no. 15), Z = 8, unit cell parameters a = 17.981(6) A, b = 5.0641(4) A, c = 24.271(6) A, and beta = 99.67(2)), the acidic OH group hydrogen-bonds intramolecularly to the adjacent pyrazolone oxygen, i.e., the two oxygen atoms are cis, true of the other Q(R') species structurally characterized here in their anionic complexed forms, in which they chelate the silver in the usual beta-diketonate manner, but not of the free anion, found in the array [Ag(Ph(3)P)(Hmimt)(2)](Q(1)) (triclinic space group P(-)1(no. 2), Z = 2, unit cell parameters a = 11.553(1) A, b = 11.943(1) A, c = 15.479(2) A, alpha = 74.829(2), beta = 76.094(2), and gamma = 78.185(2)), or [Ag(trimen)Q(1)] (monoclinic space group P2(1)/c (no. 14), Z = 4, unit cell parameters a = 7.982(1) A, b = 12.299(2) A, c = 21.507(3) A, and beta = 95.119(3)), which forms an infinite one-dimensional polymer string, Q(1) linking successive silver(I) atoms by coordination by way of the unsubstituted nitrogen and the pyrazolonate oxygen. In all [Ag(R(3)P)(2)(chelate-Q(1))] (R = Ph, Cy) complexes, P(2)Ag(O,O') arrays are found (R = Ph, monoclinic space group C2/c (no. 15), Z = 8, unit cell parameters a = 16.193(8) A, b = 13.859(7) A, c = 39.306(7) A, and beta = 100.02(3); R = Cy, triclinic space group P(-)1(no. 2), Z = 2, unit cell parameters a = 10.4655(9) A, b = 12.079(1) A, c = 22.804(2) A, alpha = 104.872(2), beta = 95.180(2), and gamma = 104.144(2)), also true of [Ag(Ph(3)P)(2)(O,O'-Q(2))] (triclinic space group P(-)1(no. 2), Z = 2, unit cell parameters a = 10.672(2) A, b = 10.710(2) A, c = 18.713(3) A, alpha = 87.573(2), beta = 80.972(2), and gamma = 81.734(2)), whereas [Ag(o-tol(3)P)Q(1)] (monoclinic space group P2(1)/c (no. 14), Z = 2 dimers, unit cell parameters a = 11.8221(6) A, b = 13.2601(6) A, c = 20.5141(10) A, and beta = 91.758(1)) exists as a dinuclear species containing two AgO(2)NP units where the acylpyrazolonate is coordinated in a bridging O,O'-Q-Nfashion. Silver atoms are four-coordinate in all except the Hmimt complex.