Carlos Yélamos

Dialkylamido derivatives of [(η5-C5Me5)TiCl3], [(η5-C5Me5) TiCl22(μ-O)] and [(η5-C5Me5)TiCl3(μ-O)3]: X-ray crystal structure of [(η5-C5Me5)Ti(NMe2)3]

Abstract Reactions of [(η5-C5Me5)TiCl3] with dialkyl and diarylamido-lithium complexes in 1:1, 1:2 or 1:3 molar ratios afford the mono(pentamethylcyclopentadienyl)titanium(IV) dialkylamido- complexes [(η5-C5Me5)TiCl3-n(NR2)n (n = 1; R = Me or SiMe3) (n = 2, R = Me or Ph) (n = 3, R = Me or Et). Similar reactions of [(η5-C5Me5)TiCl 22(μ-O)] and [(η5-C5Me5)TiCl3(μ-O)3] gave the corresponding complexes [(η5-C5Me5)TiCl2-n(NR2)ni2(μ-O)] (n = 1; R = Me or Ph) (n = 2, R = Me) and [(η5-C5Me5)3Ti3Cl3-n(NMe2)n(μ-O) 3] (n = 1 or 3). The crystal structure of [(η5-C5Me5)Ti(NMe2)3] has been established by X-ray crystallography and is shown to be monomeric with the typical three-legged piano- stool structure.

Synthesis and molecular structure of the first organometallic nitride cubane: [{Ti(η5-C5Me5)}4(µ3-N)4]

The ammonolysis of [Ti(η5-C5Me5)(NMe2)3] at 90 °C affords the nitride complex [{Ti(η5-C5Me5)}4(µ3-N)4]; the X-ray crystal structure analysis shows a Ti4N4 core clearly similar to the structural motif of cubic titanium nitride.

Rhodium/Iridium‐Titanium Azaheterometallocubanes

Treatment of [[Ti(eta5-C5Me5)(mu-NH)]3(mu3-N)] (1) with the diolefin complexes [[MCl(cod)]2] (M = Rh, Ir; cod = 1,5-cyclooctadiene) in toluene afforded the ionic complexes [M-(cod)(mu3-NH)3Ti3(eta5-C5Me5)3(mu3-N)]Cl [M = Rh (2), Ir (3)]. Reaction of complexes 2 and 3 with [Ag(BPh4)] in dichloromethane leads to anion metathesis and formation of the analogous ionic derivatives [M(cod)(mu3-NH)3Ti3-(eta5-C5Me5)3(mu3-N)][BPh4] [M = Rh (4), Ir (5)]. An X-ray crystal structure determination for 5 reveals a cube-type core [IrTi3N4] for the cationic fragment, in which 1 coordinates in a tripodal fashion to the iridium atom. Reaction of the diolefin complexes [[MCl(cod))2] (M = Rh, Ir) and [[RhCl(C2H4)2]2] with the lithium derivative [[Li(mu3-NH)2(mu3-N)-Ti3(eta5-C5Me5)3(mu3-N)]2] x C7H8 (6 C7H8) in toluene gave the neutral cube-type complexes [M(cod)(mu-NH)2(mu3-N)Ti3-(eta5-C5Me5)3(mu3-N)] [M = Rh (7), Ir (8)] and [Rh(C2H4)2(mu3-NH)2(mu3-N)Ti3(eta5-C5Me5)3(mu3-N)] (9), respectively. Density functional theory calculations have been carried out on the ionic and neutral azaheterometallocubane complexes to understand their electronic structures.

Synthesis and characterisation of chlorobis(dialkylamido) and alkylbis(dialkylamido) derivatives of [(ν5-C5Me5 )MCl3](M = Ti,Zr)

Abstract Reactions of [Cp ∗ ZrCl 3 ](Cp ∗ = ν 5 -C 5 Me 5 ) with lithium dialkyl(aryl)amidesin 1 : 1, 1: 2 or 1 : 3 molar ratios afford the dialkyl(aryl)amido complexes [Cp ∗ ZrCl 3−n (NR 2 ) n ][ n = 1, R = Et ( 1 ), Me ( 2 ), Pr i ( 3 ); n = 2, R = Et ( 4 ), Me ( 5 ), Ph ( 6 ), Pr i ( 7 ), n = 3, R = Et ( 8 ), Me ( 9 )]. Treatment of [Cp ∗ MCl(NMe 2 ) 2 ] and [Cp ∗ MCl(NPh 2 ) 2 ](M = Ti or Zr) with various alkyl- or aryl-lithium reagents generates the corresponding alkyl(aryl)bis[dialkyl(aryl)amide] derivatives [Cp ∗ MR′(NMe 2 ) 2 ] in high yield [M = Ti, R′ = CH 2 SiMe 3 ( 10 ), Me ( 12 ), Ph ( 14 ); M = Zr, R′ = CH 2 SiMe 3 ( 11 ), Me ( 13 ), R′ = Ph ( 15 )] and [Cp ∗ MMe(NPh 2 ] 2 [M = Ti ( 16 ), Zr ( 17 )].

Molecular nitrides with titanium and rare-earth metals.

A series of titanium-group 3/lanthanide metal complexes have been prepared by reaction of [{Ti(η(5)-C(5)Me(5))(μ-NH)}(3)(μ(3)-N)] (1) with halide, triflate, or amido derivatives of the rare-earth metals. Treatment of 1 with metal halide complexes [MCl(3)(thf)(n)] or metal trifluoromethanesulfonate derivatives [M(O(3)SCF(3))(3)] at room temperature affords the cube-type adducts [X(3)M{(μ(3)-NH)(3)Ti(3)(η(5)-C(5)Me(5))(3)(μ(3)-N)}] (X = Cl, M = Sc (2), Y (3), La (4), Sm (5), Er (6), Lu (7); X = OTf, M = Y (8), Sm (9), Er (10)). Treatment of yttrium (3) and lanthanum (4) halide complexes with 3 equiv of lithium 2,6-dimethylphenoxido [LiOAr] produces the aryloxido complexes [(ArO)(3)M{(μ(3)-NH)(3)Ti(3)(η(5)-C(5)Me(5))(3)(μ(3)-N)}] (M = Y (11), La (12)). Complex 1 reacts with 0.5 equiv of rare-earth bis(trimethylsilyl)amido derivatives [M{N(SiMe(3))(2)}(3)] in toluene at 85-180 °C to afford the corner-shared double-cube nitrido compounds [M(μ(3)-N)(3)(μ(3)-NH)(3){Ti(3)(η(5)-C(5)Me(5))(3)(μ(3)-N)}(2)] (M = Sc (13), Y (14), La (15), Sm (16), Eu (17), Er (18), Lu (19)) via NH(SiMe(3))(2) elimination. A single-cube intermediate [{(Me(3)Si)(2)N}Sc{(μ(3)-N)(2)(μ(3)-NH)Ti(3)(η(5)-C(5)Me(5))(3)(μ(3)-N)}] (20) was obtained by the treatment of 1 with 1 equiv of the scandium bis(trimethylsilyl)amido derivative [Sc{N(SiMe(3))(2)}(3)]. The X-ray crystal structures of 2, 7, 11, 14, 15, and 19 have been determined. The thermal decomposition in the solid state of double-cube nitrido complexes 14, 15, and 18 has been investigated by thermogravimetric analysis (TGA) and differential thermal analysis (DTA) measurements, as well as by pyrolysis experiments at 1100 °C under different atmospheres (Ar, H(2)/N(2), NH(3)) for the yttrium complex 14.

Titanium Alkali Metal Nitrido Complexes

Treatment of [(Ti(eta5-C5Me5)(mu-NH))3(mu3-N)] with alkali metal bis(trimethylsilyl)amido reagents in toluene afforded the complexes [M(mu3-N)(mu3-NH)2[Ti3(mu5-C5Me5)3(mu3-N)]]2 (M = Li (2), Na, (3), K (4)). The molecular structures of 2 and 3 have been determined by X-ray crystallographic studies and show two azaheterometallocubane cores [MTi3N4] linked by metal-nitrogen bonds. Reaction of the lithium derivative 2 with chlorotrimethylsilane or trimethyltin chloride in toluene gave the incomplete cube nitrido complexes [Ti3(eta5-C5Me5)3(mu-NH)2(mu-NMMe3)(mu3-N)] (M = Si (5), Sn (6)). A similar reaction with indium(I) or thallium(I) chlorides yielded cube-type derivatives [M(mu3-N)(mu3-NH)2[Ti(eta5-C5Me5)3(mu3-N)] (M=In (7), Tl (8)).

Molecular Nitrides with Titanium and Group 13–15 Elements

Several heterometallic nitrido complexes were prepared by reaction of the imido-nitrido titanium complex [{Ti(eta(5)-C(5)Me(5))(mu-NH)}(3)(mu(3)-N)] (1) with amido derivatives of Group 13-15 elements. Treatment of 1 with bis(trimethylsilyl)amido [M{N(SiMe(3))(2)}(3)] derivatives of aluminum, gallium, or indium in toluene at 150-190 degrees C affords the single-cube amidoaluminum complex [{(Me(3)Si)(2)N}Al{(mu(3)-N)(2)(mu(3)-NH)Ti(3)(eta(5)-C(5)Me(5))(3)(mu(3)-N)}] (2) or the corner-shared double-cube compounds [M(mu(3)-N)(3)(mu(3)-NH)(3){Ti(3)(eta(5)-C(5)Me(5))(3)(mu(3)-N)}(2)] [M = Ga (3), In (4)]. Complexes 3 and 4 were also obtained by treatment of 1 with the trialkyl derivatives [M(CH(2)SiMe(3))(3)] (M = Ga, In) at high temperatures. The analogous reaction of 1 with [{Ga(NMe(2))(3)}(2)] at 110 degrees C leads to [{Ga(mu(3)-N)(2)(mu(3)-NH)Ti(3)(eta(5)-C(5)Me(5))(3)(mu(3)-N)}(2)] (5), in which two [GaTi(3)N(4)] cube-type moieties are linked through a gallium-gallium bond. Complex 1 reacts with one equivalent of germanium, tin, or lead bis(trimethylsilyl)amido derivatives [M{N(SiMe(3))(2)}(2)] in toluene at room temperature to give cube-type complexes [M{(mu(3)-N)(2)(mu(3)-NH)Ti(3)(eta(5)-C(5)Me(5))(3)(mu(3)-N)}] [M = Ge (6), Sn (7), Pb (8)]. Monitoring the reaction of 1 with [Sn{N(SiMe(3))(2)}(2)] and [Sn(C(5)H(5))(2)] by NMR spectroscopy allows the identification of intermediates [RSn{(mu(3)-N)(mu(3)-NH)(2)Ti(3)(eta(5)-C(5)Me(5))(3)(mu(3)-N)}] [R = N(SiMe(3))(2) (9), C(5)H(5) (10)] in the formation of 7. Addition of one equivalent of the metalloligand 1 to a solution of lead derivative 8 or the treatment of 1 with a half equivalent of [Pb{N(SiMe(3))(2)}(2)] afford the corner-shared double-cube compound [Pb(mu(3)-N)(2)(mu(3)-NH)(4){Ti(3)(eta(5)-C(5)Me(5))(3)(mu(3)-N)}(2)] (11). Analogous antimony and bismuth derivatives [M(mu(3)-N)(3)(mu(3)-NH)(3){Ti(3)(eta(5)-C(5)Me(5))(3)(mu(3)-N)}(2)] [M = Sb (12), Bi (13)] were obtained through the reaction of 1 with the tris(dimethylamido) reagents [M(NMe(2))(3)]. Treatment of 1 with [AlCl(2){N(SiMe(3))(2)}(OEt(2))] affords the precipitation of the singular aluminum-titanium square-pyramidal aggregate [{{(Me(3)Si)(2)N}Cl(3)Al(2)}(mu(3)-N)(mu(3)-NH)(2){Ti(3)(eta(5)-C(5)Me(5))(3)(mu-Cl)(mu(3)-N)}] (14). The X-ray crystal structures of 5, 11, 13, 14, and [AlCl{N(SiMe(3))(2)}(2)] were determined.

Synthesis via amine elimination and characterization of new heterobimetallic complexes containing the (pentamethylcyclopentadienyl) titanium(IV) moiety

Abstract Reactions of [Cp ∗ Ti(NR 2 ) 3 ] (Cp ∗ = η 5 -C 5 Me 5 ; R = Me or Et) in a 1:1 ratio with [CpM(CO) 3 H] (M = Mo or W) lead to the formation of the heterobimetallic derivatives [Cp ∗ (R 2 N) 2 Ti(OC)M(CO) 2 Cp] ( 1–4 ), where the two metals are bridged by a carbonyl group, as is deduced by IR and 13 C NMR spectroscopies. Similar reaction of [Cp ∗ Ti(NMe 2 ) 3 ] with [CpRu(CO) 2 H] gives [Cp ∗ (Me 2 N) 2 TiRu(CO) 2 Cp]( 5 ) in which a metal-metal bond between the titanium and ruthenium atoms is proposed.

Encapsulation of a trinuclear silver(I) cluster by two imido-nitrido metalloligands [{Ti(η5-C5Me5)(μ-NH)}3(μ3-N)]

Treatment of the metalloligand [{Ti(eta(5)-C(5)Me(5))(micro-NH)}(3)(micro(3)-N)] with silver(i) trifluoromethanesulfonate in different molar ratios gives the ionic compounds [Ag{(micro(3)-NH)(3)Ti(3)(eta(5)-C(5)Me(5))(3)(micro(3)-N)}(2)][O(3)SCF(3)] and [Ag{(micro(3)-NH)(3)Ti(3)(eta(5)-C(5)Me(5))(3)(micro(3)-N)}][O(3)SCF(3)] or the triangular silver cluster [(CF(3)SO(2)O)(3)Ag(3){(micro(3)-NH)(3)Ti(3)(eta(5)-C(5)Me(5))(3)(micro(3)-N)}(2)] in which each face is capped by a metalloligand.

Hydrolysis of (pentamethylcyclopentadienyl)titanium(IV) carbamates. X-ray structure of [Cp∗ Ti(,ν2-02CNEt2)2(μ-0)2]

Abstract Complexes [Cp ∗ Ti(NR 2 ) 3 ] (Cp ∗ =gn 5 -C 5 Me 5 ; R = Me or Et) react with CO 2 to give the corresponding insertion products [Cp ∗ Ti( ν 2 -O 2 CNR 2 ) 3 ] (R = Me ( 1 ), Et ( 2 )). When solutions of 1–2 are exposed to wet air a hydrolytic process takes place and leads to the formation of the [Cp ∗ Ti(ν 2 -O 2 CNR 2 ) 2 (μ,-O) 2 ] (R = Me ( 3 ), Et ( 4 )). The molecular structure of 4 has been established by single crystal X-ray analysis.