D. Heijdenrijk

Synthesis and characterization of a stable bis-naphthyltin(II) compound.Bis[8-(dimethylamino)-1-naphthyl-C,N]tin(II) and its W(CO)5 adduct

Reaction of [8-(dimethylamino)-1-naphthyl-C, N]lithium with SnCl{2} affords the new monomeric stannylene bis[8-(dimethylamino)-1-naphthyl-C,N]tin(II) (3). The reaction between W(CO){5}(NME{3}) and 3 yields {bis[8-(dimethylamino)-1-naphthyl-C,N]tin(II)} tungsten pentacarbonyl (4). The crystal structures of 3 and 4 have been determined by X-ray diffraction methods. 3: C{2}{4}H{2}{4}N{2}Sn, orthorhombic, space group Pbca with a 22.383(4), b 30.865(5), c 12.127(2) @9 and Z = 16, final R = 0.067 for 4983 observed reflections. 4: C{2}{9}H{2}{4}N{2}O{5}SnW, a 12.509(3), b 15.191(1), c 9.780(1) @9, @a 98.42(1), @b 104.33(1), @c 107.27(1)}o{, space group P1, Z = 2, triclinic; R = 0.046 for 7116 observed reflections. The geometry about tin in 3 is distorted @j-trigonal bypyramidal, and that in 4 is distorted trigonal bipyramidal. In both 3 and 4 the 8-(dimethylamino)-1-naphthyl groups are C,N-chelate bonded, with the C(1) atoms at equatorial sites and the nitrogen atoms at axial sites. The Sn lone pair in 3 and the W(CO){5} moiety in 4 occupy the remaining equatorial sites. }1{H, }1{}3{C, and }1{}1{}9{Sn solution NMR spectroscopic studies of 3 and 4 show that at low temperature (=< - 15}o{C) they retain the structures found in the solid state. At higher temperatures fluxional processes become operative.

Oxidative-addition reactions of molecular diiodine and dibromine to divalent organotin compounds. Crystal structures of bis(8-( dimethylamino)-1-naphthyl)tin( IV) dibromide and { 2,6-(bis( dimethylamino)methyl)phenyl} - (4-tolyl) tin( IV) diodide

Abstract The reactions of bis[8-(dimethylamino)-1-naphthyl]tin(II) with dibromine or diiodine afford bis[8-(dimethylamino)-1-naphthyl]tin(IV) dibromide ( 1 ) and bis[8-(dimethylamino)-1-naphthyl]tin(IV) diiodide ( 2 ), respectively. Reaction of {2,6-[bis(dimethylamino)methyl]phenyl}(4-tolyl)tin(II) with diiodine gives {2,6-[bis(dimethylamino)Methyphenyl}(4-tolyl)tin(IV) diiodide ( 3 ) in quantitative yield. The crystal structures of 1 and 3 have been determined by X-ray diffraction methods. As a result of intramolecular coordination of the nitrogen atoms with the tin centers, the geometry about tin in both 1 and 3 is octahedral, while the carbon atoms bound to tin are in trans position. In 1 the two bromine atoms are cis to one another, as are the two nitrogen atoms, whereas in 3 the two iodine atoms, like the two nitrogen atoms, are trans to one another. 1 H, 13 C and 119 Sn solution NMR spectroscopic studies of 1–3 show that they retain the structures found in the solid state.

8-(DIMETHYLAMINO)NAPHTHYLCOPPER(I), A NOVEL STABLE ORGANOCOPPER COMPOUND WITH UNUSUAL STRUCTURAL FEATURES. ITS SYNTHESIS, CRYSTAL STRUCTURE (X-RAY), AND REACTIVITY *

Summary The synthesis and isolation of a hydrocarbon- and ether-insoluble organocopper compound containing the rigid 8-(dimethylamino)naphthyl group is described. An X-ray determination of its structure revealed a tetranuclear copper aggregate, in which the Cu atoms are arranged in a parallelogram (Cu.. . Cu 2.407(2) and 2.430(2) A) and are three-center, two-electron bridged by C(@so) (Cu-C 2.025(6) A mean) of the naphthyl group. The amine ligands coordinate pairwise to opposite copper atoms. The copper aggregate thus contains two distinct types of Cu atoms, involving two nucleophilic two-coordinate and two electrophilic four-coordinate sites, pointing to a strong cuprate character. Reaction of the organocopper compound with several copper(I) salts resulted either in the formation of binaphthyl and dimethylaminonaphthalene or a stable mixed copper cluster, depending on the anion in the copper salt. With dimethyl acetylenedicarboxylate the copper compound, without added lithium or magnesium salts, gave the (syn) addition product 8Me,NnaphthylC(CO,Me)=C(CO,Me)Cu. These reactions are discussed in relation to the structural features of the tetranuclear organocopper compound.

Synthesis and structure of [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl] methylphenyltin bromide : A novel triorganotin halide having a configurationally stable chiral tin center

Reaction of [2-(4,4-dimethyl-2-oxazoline)-S-methylphenylJcopper with dimethyltin dibromide or methylphenyltin dibromide affords [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl]dimethyltin bromide (1) and [2-(4,Cdimethyl-2-oxazoline)-5-methylphenyl]methylphenyltin bromide (2), respectively. The crystal structure of 2 has been determined by X-ray diffraction methods. C,,Hz2BrNOSn is monoclinic, space group PZ,/a with a = l&1258(9), b = 11.5704(11), c = 9.5315(6) A, /3 = 95.143(6) o and Z = 4, final R = 0.038 for 2760 observed reflections. As a result of intramolecular coordination of the nitrogen atom of the oxazoline ring to the tin atom, the geometry about tin in 1 is trigonal bipyramidal. The carbon ligands are at the equatorial sites, while the more electronegative nitrogen and bromine atoms are at the axial positions. An ‘H NMR spectroscopic study showed that in solution the chiral tin center is configurationally stable up to 120 o C (the highest temperature studied). Previously we reported on the synthesis and structural characterization in the solid state (X-ray structures) and in solution (by NMR techniques) of a series of triorganotin bromides containing C,N-chelating ligands for which the structures are schematically shown in Fig. 1. All these compounds have in common that the dimethylamino group, present in the ligand systems, is intramolecularly coordinated to the tin center. This results in a trigonal bipyramidal coordination geometry at the tin center, with the carbon ligands at the equatorial sites and the more electronegative nitrogen and bromine atoms at the axial positions. As a result of the intramolecular coordination in compounds of type A and B a six-membered chelate ring is formed [l], while in C [2], D [3-61 and E [7,8] a five-membered chelate ring is present.

Synthesis of some dinuclear Fe and Ru complexes containing an 8e donating a-diimine ligand and a m2-bridging alkyne; crystal structure of (s,s-N,N, h2,h2-C=N,C=N-1,4-diisopropyl-1,4-diaza-1,3-butadiene)(m2-methylpropynoate) tetracarbonyl diiron

Abstract Reaction of Fe2(CO)6(i-Pr-DAB) [i-Pr-DAB=i-PrNC(H)C(H)N-i-Pr] with methyl propynoate at room temperature in heptane solution, through which a stream of nitrogen is passed, yields the complex Fe2(CO)4(i-Pr-DAB)(μ2-HCCC(O)OMe) among a number of other products. The α-diimine ligand is σ,σ-N,N′,η2,η 2-CN,CN′ coordinated, thus donating eight electrons to the metal carbonyl core. This compound, of which the structure is confirmed by an X-ray crystal structure determination, is the first Fe complex with an R-DAB ligand in this coordination mode. Crystals of Fe2C16H20N2O6·0.15C6H6 are monoclinic, space group A2/a, and have cell constants a= 31.450(6), b=9.602(3), c=28.191(6) A, β=91.606(19)° and Z=16.3017 reflections (Mo Kα, μ=13.9 cm−1) have been used in the refinement resulting in a final R value of 0.056. In the compound, which is structurally analogous to the previously reported Ru2(CO)4(i-Pr-DAB)(μ2HCCH), the alkyne is in a bridging position along the metal-metal bond [Fe(11)C(15): 1.924(8); Fe(12)C(16): 2.007(7) A]. The FeFe distance of 2.670(4) A is normal for a single FeFe bond. The carbonyl ligands are all terminally bonded, two to either Fe atom, with normal bond lengths and angles. The Fe atoms and the non-H atoms of the coordinated alkyne lie in one plane, which is also a plane of symmetry in the molecule. The bond distances within the DAB ligand and between the ligand and the Fe atoms are as expected for the σ,σ-N,N′,η2, η2-CN,CN′ coordination mode. Reaction of Ru2(CO)6(i-Pr-DAB) with phenylacetylene in heptane solution at 90 °C, yields two isomeric compounds Ru2(CO)4(i-Pr-DAB)(μ2-PhC CH), which have a molecular structure comparable to that of Fe2(CO)4(i-Pr-DAB)(μ2-HCCC(O)OMe). The formation of the alkyne complexes from M2(CO)6(i-Pr-DAB) [M=Fe, Ru] probably proceeds via M2(CO)5(i-Pr-DAB) [M=Fe, Ru], through the loss of one CO with concomitant change of coordination of the i-Pr-DAB from the 6e to the 8e donating mode. Substitution of a second CO by an alkyne yields M2(CO)4(i-Pr-DAB)(μ2-RCCH) [M=Fe, R= C(O)OMe; M=Ru, R=H, Ph]. This indicates that Fe2(CO)5(i-Pr-DAB), which until now never has been observed or isolated, is a likely intermediate in reactions of Fe2(CO)6(i-Pr-DAB).

Synthesis and structure of some di-iron α-diimine complexes containing a ferracyclopentadienyl system resulting from the CC coupling of two alkynes

Abstract The dinuclear α-diimine complexes Fe2(CO)6(L) [L=R-DAB (RNCHCHNR, R=i-Pr (1a), c-Hex (1b)), i-Pr-Pyca (C5H4NCHNi-Pr)(1c)] react with two equivalents of alkyne R′CCR″ [R′=H, R″= C(O)OMe, Ph, p-Tol, CMe2OH; R′=R″=H, C(O)OMe, Ph], probably via Fe2(CO)5(σ,σ-N,N′-L)[μ2,η2R′C CR″], to give various amounts of different isomers of Fe2[C4R′2R″2](CO)4(σ,σ-N,N′-L). These complexes have a ferracyclopentadienyl fragment FeC4R′2R″2 and a chelating 4e donating α-diimine coordinated to the Fe atom bonded to the FeC4 ferracycle (3) or to the Fe atom within the ferracycle (4). Fe2[HCCHCHCH](CO)4(i-Pr-DAB) (5) is formed in the thermal reaction of 1a with ethyne and also has the α=diimine bonded to the Fe within the ferracycle. The product distribution of the reactions seems to depend mainly on steric requirements of the alkyne substituents. In some of the reactions small amounts of alkyne cyclotrimerization products were formed. The X-ray crystal structures of Fe2[PhCC(H)C(H)CPh](CO)4(σ,σ-N,N′-c-Hex-DAB) (3a), Fe2[MeOC(O)CC(H)C(C(O)OMe)CH](CO)4(σ,σ-N,N′-i-Pr-DAB) (3h), Fe2[MeOC(O)CC(C(O)OMe)C(C(O)OMe)CC(O)OMe](CO)4(σ,σ-N,N′-i-Pr-DAB) (4e) and Fe2[HCC(H)C(H)CH](CO)4(σ,σ-N,N′-i-Pr-DAB) (5) were determined. (3a (Fe2C34H36N2O4): orthorhombic crystals, space group Pbca, a=17.353(3), b=22.814(6), c=15.911(4) A, Z=8, R=0.070 for 1238 observed reflections. 3h (Fe2C20H24N2O8): monoclinic crystals, space group C2/c, a=29.609(5), b=9.969(2), c=19.611(3) A, β=127.08(1)°, Z=8, R=0.064 for 1804 observed reflections. 4e (Fe2C24H28N2O12): monoclinic crystals, space group P21/a, a=18.287(4), b=17.966(6), c=9.002(3) A, β=98.96(3)°, Z=4, R=0.076 for 1701 observed reflections. 5 (Fe2C16H20N2O4): triclinic crystals, space group P1, a= 9.8291(16), b=12.1898(22), c=9.0322(12) A, α=111.269(11)°, β=115.626(19)°, γ=79.987(23)°, Z=2, R=0.046 for 3758 observed reflections.) The complexes 4 contain a bridging CO which makes them the first ferracyclopentadienyl complexes with a bridging CO. The complexes 3 and 5 contain a semi-bridging CO. This coordination behaviour is mainly due to electronic effects. The 1H NMR spectra of the type 3 complexes with two tail-to-tail coupled alkynes show a dynamic behaviour in solution involving the back and forth rocking of the Fe(CO)(α-diimine) fragment with respect to the Fe(C4R4)(CO)3 ferracyclopentadienyl fragment.

Reversible CC coupling reactions between alkynes and CO ligands on di-iron α-diimine complexes

Abstract Fe 2 CO) 6 (L) [L=i-Pr-DAB, i-Pr-Pyca] ( 1 ) and Fe 2 (CO) 7 (2,2′-bipyridine) ( 2 ) react with RCCC- (O)OMe [R=H, C(O)OMe] to give the complexes Fe 2 [μ 2 -R′CC(R″)C(O)](CO) 5 (σ,σ-N,N′-L) [L= i-Pr-DAB: R′=H, R″=C(O)OMe ( 5a ); L=i-Pr-Pyca: R′=H, R″=C(O)OMe ( 5b ); R′=C(O)OMe, R″= H ( 5c ); R′=R″=C(O)OMe ( 5d ); L=2,2′-bipyridine (bipy): R′=R″=C(O)OMe ( 5e )] in yields varying from 2 [μ 2 -MeOC(O)CCHC(O)](CO) 5 (i-Pr-Pyca) ( 5c ) has been determined. The purple crystals of Fe 2 C 19 H 16 N 2 O 8 , M= 512.04, are triclinic, space group P 1 , a =10.1428- (11), b =10.7084(16), c =10.0367(10) A, α= 94.368(9)°, β=100.927(13)°, γ=93.552(13)°, Z = 2. A total of 2507 absorption corrected reflections (Cu Kα, μ=114.18 cm −1 ) have been used in the refinement resulting in a final R value of 0.036 ( R w = 0.054). The molecular structure of 5c consists of an Fe(CO) 3 and an Fe(CO) 2 (σ,σ-N,N′-i-Pr-Pyca) unit linked by a single FeFe bond [Fe(1)Fe(2): 2.7191(9) A], that is bridged by an organic MeOC- (O)CC(H)C(O) fragment, resulting from the CC coupling of a CO ligand and a methyl propynoate molecule. This fragment is σ-bonded via the C(C(O)- OMe) atom to the Fe(CO) 2 (Pyca) center and via the C(O) atom to the Fe(CO) 3 center to which also the olefinic bond is π-coordinated. The complexes 5 , which are most likely formed via an intermediate with a chelating α-diimine and an η 2 -CC bonded alkyne, react with a second equivalent of alkyne to give the ferracyclopentadienyl complexes Fe 2 [RCCRCRCR](CO) 4 (L). These reactions probably proceed via the fission of the CC bond between the CO and the alkyne in 5 , followed by the loss of a CO ligand. The resulting intermediate with the alkyne in the μ 2 , η 2 -perpendicular bonding mode reacts with the second alkyne molecule. Heating of 5b , c yields the ferracyclopentadienyl complexes Fe 2 [MeOC(O)CCHC(C(O)OMe)CH](CO) 4− (i-Pr-Pyca(4e)). When R′=R″=C(O)OMe ferracyclopentadienyl complexes are formed with the α-diimine bonded to the Fe in the ferracycle, whereas in the case of R′=H/C(O)OMe and R″=C(O)OMe/H the formation of ferracyclopentadienyl complexes with the α-diimine bonded to the second Fe center is observed. This product distribution is probably the result of the steric properties of the alkynes.

Intramolecular rearrangement of NN′-diaryldi-imidosulphur complexes of zerovalent platinum to a compound of bivalent platinum involving NS bond cleavage and concomitant hydrogen migration and N-C(aryl) bond formation; X-ray crystal structure of one of the products

Reaction of Pt(PPh3)2(C2H4) with NN′-diaryldi-imidosulphur ligands affords the new compounds [Pt(PPh3)2(NN′-diaryldi-imidosulphur)](arylp-tolyl, p-chlorophenyl, or m,m′-xylyl), which rearrange, as shown by spectroscopy (n.m.r., i.r., u.v.) and a single-crystal structure determination, to a bivalent platinum complex by way of NS bond breaking, N–C(aryl) bond formation, and hydrogen migration.