Reversible Insertion of Methyl Isothiocyanate into Copper(I) Aryloxides

Abstract

MeNCS undergoes insertion into the copper(I)-aryloxide bond to form [N-methylimino(aryloxy)methanethiolato]copper(I) complexes. This insertion occurs in the absence of ancillary ligands unlike the analogous insertion of PhNCS. The reaction with 4-methylphenoxide results in the formation of hexakis[[N-methylimino(4-methylphenoxy)methanethiolato]copper(I)] (1), which has been characterized by X-ray crystallography. Crystal data for 1: hexagonal R&thremacr;, a = 12.365(3) Å, c = 36.734(16) Å, gamma = 120 degrees, Z = 3, V = 4863(3) Å(3), R = 0.0306. Reactions of 2,6-dimethyl- and 4-chlorophenoxides also result in analogous copper(I) complexes 2 and 3. Addition of stochiometric amounts of PPh(3) to the oligomeric complexes typically results in the extrusion of MeNCS. The ease of extrusion is dependent on the substituents on the aryloxide, and this deinsertion is accelerated by water. However, the extrusion reaction is slow enough in the case of the N-methylimino(2,6-dimethylphenoxy)methanethiolate complex and the isolation of an intermediate monomeric product bis(triphenylphosphine)[N-methylimino(2,6-dimethylphenoxy)methanethiolato]copper(I) (4) is possible. Crystal data for 4: triclinic P&onemacr;, a = 10.088(2) Å, b = 11.302(1) Å, c = 17.990(2) Å, alpha = 94.06(1) degrees, beta = 95.22(2) degrees, gamma = 103.94(1) degrees, Z = 2, V = 1974.4(7) Å(3), R = 0.0361. In the presence of of PPh(3), the insertion reaction becomes reversible. This allows the exchange of the heterocumulene MeNCS or the aryloxy group in these molecules with another heterocumulene or a phenol, respectively, when catalytic amounts of PPh(3) are added. Oligomers with exchanged heterocumulmes and phenols could be characterized by independent synthesis.

Subnanometer-Sized Copper Clusters: A Critical Re-evaluation of the Synthesis and Characterization of Cu8(MPP)4 (HMPP = 2-Mercapto-5-n-propylpyrimidine)

“…Each Cu atom is coordinated by two S atoms and an N atom, which are provided by the MPP ligand. Notably, this is the same core structure found in a number of Cu 6 complexes with anionic S , N chelating ligands, − ,− such as [Cu­{μ 2 -SC­(NPh)­(OC 6 H 4 -4-Me)}] 6 and [Cu­(Hmna)] 6 (H 2 mna = 2-mercapto nicotinic acid). , The range of Cu–Cu distances in [Cu­(MPP)] 6 (2.6282(2)–3.072 (2) Å) is comparable to those observed in complexes with the same core structure (2.711–3.465 Å). − In addition, the N–C and C–C bond lengths within the pyrimidine ring are consistent with the presence of an intact aromatic ring (Figure S2) and are notably different from the intraring distances observed for [Cu­(HMPP*)] 4 . The average Cu–N and Cu–S bond lengths (2.04 and 2.25 Å, respectively) are also typical of Cu 6 complexes decorated with anionic S , N chelates (Cu–N, 1.99–2.04 Å; Cu–S, 2.24–2.25 Å).…”

“…Each Cu atom is coordinated by two S atoms and a N atom, which are provided by the HMPP* ligands. The Cu–Cu distances within the tetrahedral core feature a large range (2.5934(4)–2.9742(6) Å) but are within the parameters typically observed for Cu­(I) cluster complexes. − The average Cu–N and Cu–S bond lengths (1.99 and 2.27 Å, respectively) are also typical of Cu clusters decorated with anionic S , N chelates. − In addition, the N–C and C–C bond lengths within the ring support the presence of the dihydropyrimidine moiety. For example, the C11–C10 (1.354(4) Å) and C9–C10 (1.442(4) Å) bond lengths are consistent with double and single bonds, respectively (Figure b).…”

In-Situ Ligand Formation-Driven Preparation of a Heterometallic Metal–Organic Framework for Highly Selective Separation of Light Hydrocarbons and Efficient Mercury Adsorption

“…The In 3+ center exhibits an eight-coordinated distorted tetrahedral geometry, binding with eight O atoms from four independent L 2– ligands; the In–O bond lengths range from 2.218(3) to 2.314(3) Å. Cu + ion is trigonal coordinated by one pyridyl N atom and two S atoms from three independent L 2– ligands, where the observed Cu–S and Cu–N bond lengths are 2.251(10) and 2.052(4) Å, respectively. In the coordination environment of trifunctional L 2– ligand, it utilizes a carboxylate group to chelate an eight-coordinated In 3+ ion to constitute a classic 4-connected In­(COO) 4 moiety, while it takes its remaining N- and S-donor centers to link three Cu + ions to make a unique Cu 6 S 6 cluster (Figure a and b), which is very different from the reported analogues. − The combination of one Cu 6 S 6 and six L 2– can be thus viewed as a novel hexadentate carboxylic ligand, typically a metalloligand (Figure c). The solvent-accessible volume in BUT-52 estimated by PLATON is 67.4% of the total volume (potential solvent area volume = 7221.3 Å 3 ; per unit cell volume = 10718.4 Å 3 ), after removing all of the guest solvent molecules and [(CH 3 ) 2 NH 2 ] + .…”

Reactivity of ortho‐Substituted Aryl–Palladium Complexes towards Carbodiimides, Isothiocyanates, Nitriles, and Cyanamides

“…Isothiocyanates insert into MÀO (M= Re, [44,45] Ni, [46] Cu, [47] Zn [48] ), MÀN (M= Mg, [34] Yb, [39] Ln, [38,49] Re, [50] Fe, [51] Ni, [46] Pd, [52] ), MÀH (M= Zr, [53] Nb, Ta, [54] Ru, Os, Ir, [55] Rh [56] ), M À S (M= Nd [57] ), and M À C (M= Mg, [34,58] Al, [59] Zr, [60] Nb, Ta, [61] Re, [62] Fe, [63] Co, [64] Ni, [65] Pd [10] ) bonds in the same way as carbodiimides. We have recently reported the first example of insertion of an isothiocyanate into a Pd À C bond followed by formation of PdS.…”