Studies of polarized ethylenes—VIII

Synthesis and investigation of new cyclic haloamidinium salts

The presented work describes the synthesis of new six- and seven-membered haloamidinium salts and their reaction with different metals. The isolated metal complexes were tested in a catalytic reaction. Two different synthetic routes were applied to prepare five different salts. Chloroamidinium salts were very water-sensitive in comparison to their corresponding bromoamidinium salts. Hence, the preparation of the less sensitive bromoamidinium salts was higher prioritized. The formed salts were converted with metal sources to N-heterocyclic carbene (NHC) metal complexes through an oxidative insertion into the C–X bond. This type of formation is less examined for the synthesis of extended NHC metal complexes. Pd(PPh3)4 and cobalt powder were applied as metal sources, whereby two palladium complexes were isolated, characterized, and their crystal and molecular structures determined. The palladium complexes were investigated in the Suzuki-Miyaura reaction and showed promising catalytic activity.

1,1-diamino-2,2-dinitroethylenes are always zwitterions

The nitration of tetraiodoethylene (7) yields 1,1-diiodo-2,2-dinitroethylene (8). The latter reacts with alkylamines 9 or alkyldiamines 11 to give the corresponding acyclic 1,1-diamino-2,2-dinitroethylenes 10 or their cyclic analogs 12, respectively. On the basis of liquid and solid-state (13)C and (15)N NMR data, x-ray analysis and ab initio calculations, we suggest that the title compounds are always zwitterionic and that the C(A)-C(N) bond is not a true double bond.

1,1-ethylenedithiolato complexes of palladium(II) and platinum(II) with isocyanide and carbene ligands

The reactions of [Tl(2)[S(2)C=C[C(O)Me](2)]](n) with [MCl(2)(NCPh)(2)] and CNR (1:1:2) give complexes [M[eta(2)-S(2)C=C[C(O)Me](2)](CNR)(2)] [R = (t)Bu, M = Pd (1a), Pt (1b); R = C(6)H(3)Me(2)-2,6 (Xy), M = Pd (2a), Pt (2b)]. Compound 1b reacts with AgClO(4) (1:1) to give [[Pt(CN(t)Bu)(2)](2)Ag(2)[mu(2),eta(2)-(S,S')-[S(2)C=C[C(O)Me](2)](2)]](ClO(4))(2) (3). The reactions of 1 or 2 with diethylamine give mixed isocyanide carbene complexes [M[eta(2)-S(2)C=C[C(O)Me](2)](CNR)[C(NEt(2))(NHR)]] [R = (t)Bu, M = Pd (4a), Pt (4b); R = Xy, M = Pd (5a), Pt (5b)] regardless of the molar ratio of the reagents. The same complexes react with an excess of ammonia to give [M[eta(2)-(S,S')-S(2)C=C[C(O)Me](2)](CN(t)Bu)[C(NH(2))(NH(t)Bu)]] [M = Pd (6a), Pt (6b)] or [M[eta(2)-(S,S')-S(2)C=C[C(O)Me](2)][C(NH(2))(NHXy)](2)] [M = Pd (7a), Pt (7b)] probably depending on steric factors. The crystal structures of 2b, 4a, and 4b have been determined. Compounds 4a and 4b are isostructural. They all display distorted square planar metal environments and chelating planar E,Z-2,2-diacetyl-1,1-ethylenedithiolato ligands that coordinate through the sulfur atoms.

Heterodi- [MAg, MAu (M = Pd, Pt)], Tri- [PdAg(2), PtAg(2), PtAu(2), Pt(2)M (M = Ni, Pt, Cd, Hg)], and Tetranuclear (Pt(2)Ag(2), Pt(2)Au(2)) 1,1-ethylenedithiolato complexes

The reactions of [M(PPh(3))(2)[S(2)C=C[C(O)Me](2)]] [M = Pd (1a), Pt (1b)] with AgClO(4) and PPh(3) or with [Au(PPh(3))(OCMe(2))]ClO(4) afford heterodinuclear [[M(PPh(3))(2)][M'(PPh(3))][S(2)C=C[C(O)Me](2)]]ClO(4) [M = Pd, M' = Ag (2a), M = Pt, M' = Ag (2b), Au (4)] or trinuclear [[M(PPh(3))(2)][M'(PPh(3))](2)[S(2)C=C[C(O)Me](2)]](ClO(4))(2) [M = Pd, M' = Ag (3a), M = Pt, M' = Ag (3b), Au (5)] 1,1-ethylenedithiolato complexes, depending on the molar ratio of the reagents. We have recently reported that, in the absence of added PPh(3), the reactions of [Pt[S(2)C=C[C(O)Me](2)]L(2)] [L = PPh(3) (1b), L(2) = 1,5-cyclooctadiene (cod) (1c)] with AgClO(4) produce the heterotetranuclear derivatives [[PtL(2)](2)Ag(2)[S(2)C=C[C(O)Me](2)](2)]](ClO(4))(2) [L = PPh(3) (6a), L(2) = cod (6b)], which have been used now as efficient transmetallating agents toward gold, platinum, mercury, nickel, copper, or cadmium metal centers to give new types of 1,1-ethylenedithiolato complexes: [[Pt(PPh(3))(2)](2)Au(2)[S(2)C=C[C(O)Me](2)](2)](ClO(4))(2) (7), [(PtL(2))(2)M[S(2)C=C[C(O)Me](2)](2)](ClO(4))(2) [L(2) = cod, M = Pt (8), L = PPh(3), M = Hg (9)], [[Pt(PPh(3))(2)](2)[S(2)C=C[C(Me)=O](2)](2)Ni](ClO(4))(2) (10), and [[Pt(PPh(3))(2)](2)[S(2)C=C[C(Me)=O](2)](2)[M(OClO(3))(2)]] [M = Cu (11), [C(O)Me](2)] moieties but, whereas in 7 they bridge two gold(I) centers through the sulfur atoms, in 11 they chelate the copper(II) center through the oxygen atoms. The last one is the first example of such a coordination mode for the 2,2-diacetyl-1,1-ethylenedithiolato ligand.

Mononuclear (Pd, Pt), heterodinuclear (PdAg, PtAg), and tetranuclear (Pd2Ag2, Pt2Ag2) 1,1-ethylenedithiolato complexes

lp;&-5q;1 The reactions of [Tl2[S2C=C[C(O)Me]2]]n with [MCl2L2] (1:1) or with [MCl2(NCPh)2] and PPh3 (1:1:2) give complexes [M[eta2-S2C=C[C(O)Me]2]L2] [M = Pt, L2 = 1,5-cyclooctadiene (cod) (1); L2 = bpy, M = Pd (2a), Pt (2b), L = PPh3, M = Pd (3a), Pt (3b)] whereas with MCl2 and QCl (2:1:2) anionic derivatives Q2[M[eta2-S2C=C[C(O)Me]2]2] [M = Pd, Q = NMe4 (4a), Ph3P=N=PPh3 (PPN) (4a'), M = Pt, Q = NMe4 (4b)] are produced. Complexes 1 and 3 react with AgClO4 (1:1) to give tetranuclear complexes [[ML2]2Ag2[mu2,eta2-(S,S')-[S2C=C[C(O)Me]2]2]](ClO4)2 [L = PPh3, M = Pd (5a), Pt (5b), L2 = cod, M = Pt (5b')], while the reactions of 3 with AgClO4 and PPh3 (1:1:2) give dinuclear [[M(PPh3)2][Ag(PPh3)2][mu2,eta2-(S,S')-S2C=C[C(O)Me]2]]]ClO4 [M = Pd (6a), Pt (6b)]. The crystal structures of 3a, 3b, 4a, and two crystal forms of 5b have been determined. The two crystal forms of 5b display two [Pt(PPh3)2][mu2,eta2-(S,S')-[S2C=C[C(O)Me]2]2] moieties bridging two Ag(I) centers.

Complexes with S-Donor Ligands. 7. New 1,1-Ethylenedithiolato Complexes of Thallium(I), Gold(I), and Gold(III): Syntheses, Structure, and Molecular Cubic Hyperpolarizabilities

beta-Diketonato complexes [Tl{CH{C(O)R}(2)}] or PPN[Au{CH{C(O)R}(2)}(2)] [where PPN = (Ph(3)P)(2)N] react with an excess of CS(2) to give, respectively, [Tl(2){S(2)C=C{C(O)R}(2)}](n)() [R = Me (1) or Ph (2)] or (PPN)(2)[Au(2){&mgr;-kappa(2)-S(2)C=C{C(O)R}(2)}(2)] [R = Me (3.PPN) or Ph (4.PPN)]. The gold complexes 3.PPN and 4.PPN can also be obtained from PPN[AuCl(2)] and the corresponding thallium 1,1-ethylenedithiolate. PPN[AuCl(4)] reacts with 1 to give PPN[Au{kappa(2)-S(2)C=C{C(O)Me}(2)}(2)] (5) which, in turn, reacts with PhICl(2), Br(2) or I(2) (1:1) to give PPN[AuX(2){kappa(2)-S(2)C=C{C(O)Me}(2)}] [X = Cl (6), Br (7), or I (8)]. By reacting 6 with TlCF(3)SO(3) and 1,10-phenanthroline (phen) in 1:2:1 molar ratio, the cationic complex [Au{kappa(2)-S(2)C=C{C(O)Me}(2)}(phen)]CF(3)SO(3) (9) can be obtained. The crystal structures of 5 and 6.0.5Me(2)CO have been determined. Third-order nonlinearities of 3.PPN, 3.Pr(4)N, 5, and 6 have been evaluated by the Z-scan technique; an increase in nonlinearity upon extending the pi-system is observed, with the anionic dimetallacycle containing two gold and four sulfur atoms in 3 responsible for the largest nonlinearities (approximately 100 x 10(-36) esu).