Product of a DMF Aminalization, Bis[bis(3,5-dimethylpyrazol-1-yl)(dimethylamino)methane]copper(II) Perchlorate−Bis(dichloromethane)

Abstract

Bis[bis(3,5-dimethylpyrazol-1-yl)(dimethylamino)methane]copper(II) perchlorate−bis(dichloromethane), Cu(II)(1)2(ClO4)2·2CH2Cl2 , 2, is the unanticipated product of the reaction of tris(3,5-dimethylpyrazol-1-yl)methylsilane, 3, with Cu(II)(DMF)4 (ClO4)2. In the title complex, the Cu(II)(1)2 cations exhibit a tetragonal Cu(II)N6 geometry arising from coordination of four pyrazole N atoms and two tertiary amine N atoms from two bis(3,5-dimethylpyrazol-1-yl)(dimethylamino)methane ligands, 1. The tridentate (N)3 ligands 1 coordinate copper facially with one Cu−N (pyrazole) axial [Cu−N, 2.407(4) Å] and the second equatorial [Cu−N, 1.995(4) Å]; the cations exhibit crystallographic 2-fold symmetry that relates one ligand to the other. Cu(II)(1)2(ClO4)2·2CH2Cl2, CuC28H46Cl6N10O8·2CH2Cl2, crystallizes in the monoclinic space group C2/c, with a = 26.278(5) Å, b = 8.835(2) Å, c = 20.655(4) Å, β = 120.73(3)°, Z = 4, and R F (R wF 2) = 0.049 (0.122) for 1979 observed reflections with I > 2σ(I). Crystals of 2 are stable in dry air but hydrolyze readily to yield dimethylformamide and 3,5-dimethylpyrazole. A mechanism is proposed for the formation of complex 2 by silane-promoted aminalization (an aminal is the diaza analogue of an acetal) of dimethylformamide.

Group 11 complexes with the bis(3,5-dimethylpyrazol-1-yl)methane ligand. How secondary bonds can influence the coordination environment of Ag(i): the role of coordinated water in [Ag2(µ-L)2(OH2)2](OTf)2

“…In the mass spectrum of 1, the molecular or the cation molecular peaks are not present; other peaks are present as for example [CuL 2 (NCMe) 2 ] + at m/z 553 (49%) and [CuL(NCMe) 2 ] + at m/z 349 (100%) probably arising at association processes. Complex 2 shows similar resonances in the 1 H and 13 C NMR spectra for the ligand L, although with different chemical shifts (see Experimental section). The mass spectrum shows the cation molecular peak at m/z 773 [Ag 2 (OTf)L 2 ] + (10%).…”

“…NMR spectra were recorded on a Varian Unity 300 spectrometer and a Bruker ARX 300 or Bruker Avance 400 spectrometers in CDCl 3 or CD 2 Cl 2 . Chemical shifts are cited relative to SiMe 4 ( 1 H, 13 C, external), CFCl 3 ( 19 F, external) and 85% H 3 PO 4 ( 31 P, external). Infrared spectra were recorded in the range 4000-350 cm −1 on a Perkin-Elmer Spectrum One spectrophotometer using Nujol mulls between polyethylene sheets or KBr pellets.…”

“…As we comment below the structure of 2 crystallizes with two water molecules, however in the 1 H NMR spectra these molecules are not observed. The 13 C NMR spectra of 1 show the resonances for the carbon atoms of the pyrazole rings, C3, C4, C5 at 142.40, 103.28 and 152.28 ppm, respectively. The methylene carbon appears at 57.39, the methyl carbons at 13.99 and 11.25 and the methyl from the MeCN at 3.26 ppm.…”

“…Found: C, 49.52; H, 4.38; N, 7.60; S, 4.21. 1 H NMR, CDCl 3 , d: 7.55-7.45 (m, 15 H, Ph), 6.43 (s, CH 2 ), 5.88 (s, H4), 2.48 (s, CH 3 ), 1.95 (s, CH 3 ) ppm 13. C NMR, CDCl 3 , d: 150.62 (C5), 142.13 (C3), 133.95 (C o ), 133.79 (C o ), 131.23 (C p , Ph), 130.10 (d, C ipso , J(PC) 38.20 Hz), 129.39 (C m ), 129.28 (C m ), 106.82 (C4), 58.45 (CH 2 ), 14.14 (CH 3 ), 11.17 (CH 3 ) ppm.…”

Bis[2-(cyclopropyliminomethyl)-5-methoxyphenolato]zinc(II)

“…For metal complexes with pyrazole, see: ; Stibrany et al (1999Stibrany et al ( , 2005. Copper and cobalt complexes utlizing the title ligand have been prepared for oxidation studies, see: Gorun et al (2000).…”