Nitridorhenium(V) Complexes with 1,3‐Dialkyl‐4,5‐dimethylimidazole‐2‐ylidenes

The nitridorhenium(V) complexes [ReNCl₂(PR₂Ph)₃] (R = Me, Et) react with the N‐heterocyclic carbenes (NHC) 1,3‐diethyl‐4,5‐dimethylimidazole‐5‐ylidene (L^Et) or 1,3,4,5‐tetramethylimidazole‐2‐ylidene (L^Me) in absolutely dry THF under complete replacement of the equatorial coordination sphere. The resulting [ReNCl(L^R)₄]⁺ complexes (L^R = L^Me, L^Et) are moderately stable as solids and in solution, but decompose in hot methanol under formation of [ReO₂(L^R)₄]⁺ complexes. With 1,3‐diisopropyl‐4,5‐dimethylimidazole‐5‐ylidene (L^i‐Pr), the loss of the nitrido ligand and the formation of a dioxo species is more rapid and no nitridorhenium intermediate could be isolated. The Re‐C bond lengths in [ReNCl(L^Et)₄]Cl of approximately 2.195Å are relatively long and indicate mainly σ‐bonding in the electron‐deficient d² system under study. The hydrolysis of the nitrido complexes proceeds via the formation of [ReO₃N]^2? anions as could be verified by the isolation and structural characterization of the intermediates [{ReN(PMe₂Ph)₃}{ReO₃N}]₂ and [{ReN(OH₂)(L^Et)₂}₂O][ReO₃N].     

Synthesis and Crystal Structures of the Novel Tetrameric Nitrido Complexes [{cyclo-ReN}4(S2CNEt2)6(MeOH)2(PPh3)2][BPh4]2 · CH2Cl2 · 2 H2O and [{cyclo-ReN}4(S2CNEt2)4Cl4(PMe2Ph)4] · 2 acetone

Novel tetrameric rhenium(V) complexes have been prepared from [ReNCl₂(PPh₃)₂] and [ReN(PMe₂Ph)(S₂CNEt)₂], respectively. [ReNCl₂(PPh₃)₂] reacts with 1.5 equivalents of KS₂CNEt₂ in methanol to yield the unusual dark red species [{cyclo-ReN}₄(S₂CNEt₂)₆(MeOH)₂(PPh₃)₂][BPh₄]₂ · CH₂Cl₂ · 2 H₂O ( 1 ). The crystal structure of the tetramer (triclinic, space group P1, a = 13.842(2), b = 15.213(2), c = 16.796(3) Å, α = 67.88(1), β = 70.90(1), γ = 88.05(1)°, U = 3080.2(8) ų, Z = 1) shows four rhenium atoms in a square configuration which are bridged via linear asymmetric Re≡N–Re groups with bond lengths of about 169 and 203 pm. The molecule contains a centre of symmetry with two distinct octahedral rhenium environments. The first rhenium environment contains two bidentate dithiocarbamate ligands which complete the octahedral geometry and the second contains a bidentate dithiocarbamate ligand, coordinated methanol and has retained a single phosphine coligand. A symmetric compound containing the {cyclo-ReN}₄ core is obtained from the reaction of [ReN(PMe₂Ph)(S₂CNEt₂)₂] with Al₂Cl₆ in acetone. [{cyclo-ReN}₄(S₂CNEt₂)₄Cl₄(PMe₂Ph)₄] · 2 acetone ( 2 ) forms red crystals (monoclinic, space group C2/c, a = 21.432(6), b = 13.700(3), c = 28.060(9) Å, β = 102.37(1)°, U = 8048(4) Å3, Z = 4) with each rhenium atom coordinated by a bidentate dithiocarbamato, a phosphine and a chloro ligand. The non-planar 8-membered {ReN}₄ ring contains asymmetric Re≡N–Re bridges (mean values: 1.69 Å and 2.029 Å, respectively). In contrast, reaction of [ReNCl(S₂CNEt₂)(PMe₂Ph)₂] with one equivalent of K[S₂CN(Me)CH₂CH₂NMe₃]I gave the mixed dithiocarbamato-cation [ReN(S₂CNEt₂)(S₂CN(Me)CH₂CH₂NMe₃)(PMe₂Ph)]⁺ ( 3 ) which was isolated as a tetraphenylborate salt.     

Synthese und Struktur von [(Me2PhP)3Cl2ReN]2NbCl4 und [Re3N3Cl5(PMe2Ph)6][NbCl6]

Synthesis and Structure of [(Me₂PhP)₃Cl₂ReN]₂NbCl₄ and [Re₃N₃Cl₅(PMe₂Ph)₆][NbCl₆] The reaction of ReNCl₂(PMe₂Ph)₃ with NbCl₅ in toluene yields the trinuclear complexes [(Me₂PhP)₃Cl₂ReN]₂‐ NbCl₄ (1) and [Re₃N₃Cl₅(PMe₂Ph)₆][NbCl₆] ( 2 ). 1 forms triclinic crystals with the composition 1 · 2 C₇H₈ (P 1, a = 1074.5(1), b = 1289.1(2), c = 1299.3(2) pm, α = 85.25(2)°, β = 81.04(2)°, γ = 86.02(1)°, Z = 1). In the centrosymmetric compound 1 two complexes ReNCl₂(PMe₂Ph)₃ coordinate with their nitrido ligands a square planar, central unit NbCl₄ to form an almost linear arrangement Re≡N–Nb–N≡Re. The length of the Re–N triple bonds is 172,2 pm, and the Nb–N distances of 216.0 pm correspond to coordinative single bonds. 2 forms orthorhombic crystals with the space group P2₁2₁2₁ and a = 1286.0(1), b = 2109.2(4), c = 2436.2(3) pm, Z = 4. The three Re atoms are located at the corners of a triangle. They are connected by two asymmetric nitrido bridges and two asymmetric chloro bridges. The weakly bent nitrido bridges (Re–N–Re = 152° and 157°) are characterized by Re–N distances of 169 und 207 pm as well as 171 and 207 pm. Re1, in addition, binds a terminal nitrido ligand with Re1–N1 = 166 pm.     

Phosphaniminato‐Komplexe von Rhenium(VII). Synthesen und Kristallstrukturen von [ReO3(NPR3)] (R = Ph,Et) sowie von [ReO(OSiMe3)3(Me3SiNPEt3)]

Phosphoraneiminato Complexes of Rhenium(VII). Syntheses and Crystal Structures of [ReO₃(NPR₃)] (R = Ph, Et) and of [ReO(OSiMe₃)₃(Me₃SiNPEt₃)] The phosphoraneiminato complexes [ReO₃(NPR₃)] with R = Ph ( 1 ) and R = Et ( 2 ) are made from dirhenium heptaoxide and the silylated phosphoraneimines Me₃SiNPR₃. The complexes 1 and 2 as well as the red silanolate [ReO(OSiMe₃)₃(Me₃SiNPEt₃)] ( 3 ), which is formed as a by‐product in the synthesis of 2 , are characterized crystallographically. 1 and 2 are monomeric molecules, in which the phosphoraneiminato ligands NPR₃^– realize short ReN bonds of 179.3 pm ( 1 ) and 178.6 pm ( 2 ), respectively, with large ReNP bond angles of 162.0° ( 1 ) and 160.6° ( 2 ), respectively. In the rhenium(V) complex 3 the oxoligand occupies the apical position of the tetragonal pyramidal coordination of the rhenium atom, while the oxygen atoms of the Me₃SiO^– groups take the basic positions along with the nitrogen atom of the phosphaneimine molecule.     

Synthese und Kristallstrukturen der mehrkernigen Rhenium–Nitrido‐Komplexe [Re2N2Cl4(PMe2Ph)4(MeCN)] und [Re4N3Cl9(PMe2Ph)6]

Synthesis and Structures of the Multinuclear Rhenium Nitrido Complexes [Re₂N₂Cl₄(PMe₂Ph)₄(MeCN)] and [Re₄N₃Cl₉(PMe₂Ph)₆] The binuclear rhenium complex [Re₂N₂Cl₄(PMe₂Ph)₄(MeCN)] ( 1 ) is obtained as a byproduct of the synthesis of [(Me₂PhP)₃(MeCN)ClReNZrCl₅] from [ReNCl₂(PMe₂Ph)₃] and [ZrCl₄(MeCN)₂] in toluene. It crystallizes as 1 · 2 toluene in the monoclinic space group P2₁/n with a = 1517.0(3); b = 1847.7(2); c = 1952.4(6) pm; β = 106.44(1)° and Z = 4. The two Re atoms are connected by an asymmetric nitrido bridge Re≡N–Re with distances Re–N of 169.9(5) and 208.7(5) pm. In course of the reaction of [ReNCl₂(PMe₂Ph)₃] with [ZrCl₄(THF)₂] in CH₂Cl₂ hydrochloric acid is formed by acting of the Lewis acid on the solvent. HCl protonates and eliminates phosphine ligands of the educt [ReNCl₂(PMe₂Ph)₃] to form the phosphonium salt [PMe₂PhH]₂[ZrCl₆] ( 2 ). It crystallizes in the monoclinic space group C2/c with a = 1536.9(3); b = 1148.8(1); c = 1402.2(3) pm, β = 100.70(2)° and Z = 4. The remaining fragments of the rhenium complex combine to yield the tetranuclear mixed valent complex [Re₄N₃Cl₉(PMe₂Ph)₆] ( 3 ), crystallizing as 3 · CH₂Cl₂ in the triclinic space group P 1 with a = 1312.9(19); b = 1661.4(2); 1897.1(2) pm; α = 78.62(1)°; β = 86.77(1)°; γ = 68.28(1)° and Z = 2. The four Re atoms occupy the corners of a tetrahedron. Its edges are formed by three nitrido and three chloro bridges. The asymmetric nitrido bridges Re≡N–Re are characterized by short distances in the range of 172(2) to 176(3) pm and long distances of 194(3) to 204(2) pm. The angles Re–N–Re are between 154(1) and 160(1)°.     

[{ReN(Me2PhP)(Et2dtc)Cl}2{ReN(Et22tc)2}2{SbCl3}2] — ein neuer vierkerniger Rheniumkomplex mit asymmetrischen Nitridobrücken

[{ReN(Me₂PhP)(Et₂dtc)Cl}₂{ReN(Et₂dtc)₂}₂{SbCl₃}₂] — a Novel Tetranuclear Rhenium Complex with Asymmetric Nitrido Bridges The reaction of [ReN(Et₂dtc)₂(Me2₂hP)] (Me₂PhP = dimethylphenylphosphine, Et₂dtc^‐ = diethyldithiocarbamate) with SbCl₃ in dichloromethane results in the formation of [{ReN(Me₂PhP)(Et2₂tc)Cl}₂{ReN(Et₂dtc)₂}₂{SbCl₃}₂]. A {Re≡N‐}₄ ring with asymmetric nitrido bridges is stabilised by the co‐ordination of SbCl₃ onto the chloro ligands and sulphur atoms of the dithiocarbamates. The compound decomposes upon heating in acetonitrile and the fragments of the tetrameric complex re‐arrange to form [ReN‐(Me₂PhP)(Et₂dtc)Cl]₄ and [ReN(Et₂dtc)₂]. The multinuclear rhenium compounds have been studied by X‐ray crystallography. The 8‐membered {Re≡N‐}₄ ring system in [{ReN(Me₂PhP)(Et₂dtc)Cl}2₂ReN(Et₂dtc)₂}₂{SbCl₃}₂] is almost planar, while that of [ReN(Me₂PhP)(Et₂dtc)Cl]₄ is clearly V‐shaped when viewed down either diagonal Re…Re axis. A dihedral angle of 47.88(2)° has been found between the contributing planes.     

Synthese und Struktur von [Re(NH)Cl2(PMe2Ph)3][TaCl6] und [(Me2PhP)3Cl2Re≡N]2VOCl2

Synthesis and Structure of [Re(NH)Cl₂(PMe₂Ph)₃][TaCl₆] and [(Me₂PhP)₃Cl₂Re≡N]₂VOCl₂ The products of the reaction of ReNCl₂(PMe₂Ph)₃ with TaCl₅ are dependent on the solvent. In CH₂Cl₂ the solvent protonates the nitrido ligand to yield [Re(NH)Cl₂(PMe₂Ph)₃][TaCl₆] as air-stable, reddish brown needles with the space group P2₁/n and a = 1213.8(3), b = 1358.0(2), c = 2165.9(4) pm, β = 92.88(1)°, Z = 4. The Re atom of the cation exhibits an octahedral coordination with the phosphine ligands in meridional arrangement. The imido ligand is in trans-position to a Cl atom with a distance Re–N = 170.4(4) pm. When the reaction is carried out in toluene the dinuclear nitrido complex [Re(NTaCl₅)Cl₂(PMe₂Ph)₃] is obtained instead. The reaction of ReNCl₂(PMe₂Ph)₃ with VCl₃(THF)₃ in toluene affords the threenuclear complex [Re₂N₂Cl₄(PMe₂Ph)₅]VCl₃, which upon crystallization at air gives air-stable, reddish-brown crystals of [(Me₂PhP)₃Cl₂ReN]₂VOCl₂. They crystallize in the monoclinic space group P2₁ with a = 1519.2(5), b = 1257.1(1), c = 1564.3(6) pm, β = 102.86(2)°, and Z = 2. The threenuclear complex shows an almost linear arrangement Re≡N–V–N≡Re with distances Re–N 171(2) pm and V–N of 209(2) pm.     

Synthese und Struktur von (Me2PhP)3Cl2Re≡N–ReCl4(PMe2Ph), einem gemischtvalenten Zweikernkomplex mit einer Nitridobrücke zwischen ReV und ReIV

Synthesis and Structure of (Me₂PhP)₃Cl₂Re≡N–ReCl₄(PMe₂Ph), a Mixed Valent Dinuclear Complex with a Nitrido Bridge between Re^V and Re^IV The nitrido complex (Me₂PhP)₃Cl₂Re≡N–ReCl₄(PMe₂Ph) results from the reaction of ReNCl₂(PMe₂Ph)₃ with GeCl₄ in toluene. The mixed valent dinuclear complex is paramagnetic with μ_eff = 1.96 B. M. at 300 K. It crystallizes with one solvate molecule as red crystals (Me₂PhP)₃Cl₂Re≡N–ReCl₄(PMe₂Ph) · C₇H₈ with the space group P 1 and a = 1075.4(6), b = 1330.5(6), c = 1745.3(11) pm, α = 101.20(3), β = 105.88(3), γ = 94.23(3)°, Z = 2. In the dinuclear complex one molecule ReNCl₂(PMe₂Ph)₃ coordinates with its nitrido ligand to a fragment ReCl₄(PMe₂Ph). The resulting nitrido bridge is asymmetrical with distances Re–N of 170.6(6) and 205.5(6) pm, and a bond angle Re1–N–Re2 = 174.6(3)°.     

Synthese und Struktur von [(Me2PhP)3Cl2ReN]2ReCl4, [(Me2PhP)3Cl2ReN]2ReCl4 · 2 SbCl3 und [Re(NH)Cl2(PMe2Ph)3][SbCl6]

Synthesis and Structure of [(Me₂PhP)₃Cl₂ReN]₂ReCl₄, [(Me₂PhP)₃Cl₂ReN]₂ReCl₄ · 2 SbCl₃ and [Re(NH)Cl₂(PMe₂Ph)₃][SbCl₆] The reaction of ReNCl₂(PMePh)₃ with SbCl₅ in toluene yields the trinuclear complex [(Me₂PhP)₃Cl₂Re≡N]₂ReCl₄ · 2 SbCl₃ ( 1 · 2 SbCl₃). It forms triclinic crystals with the composition 1 · 2 SbCl₃, as well as monoclinic crystals 1 · 2 SbCl₃ · 4 C₇H₈. The monoclinic crystals with the space group P2₁/c, and a = 1212.3(2), b = 2098.5(4), c = 1827.7(3) pm, β = 95.51(1)°, Z = 2, have been used for a crystal structure determination. In the centrosymmetric complex 1 two complexes ReNCl₂(PMe₂Ph)₃ coordinate with their nitrido ligands a square planar, central unit ReCl₄. The SbCl₃ molecules are coordinated by chlorine bridges to Cl atoms of 1 , and, in addition, connect the complexes 1 with each other. The SbCl₃ free compound 1 is obtained in good yield by the reaction of ReNCl₂(PMePh)₃ with ReCl₄(NCEt)₂. It crystallizes in the triclinic space group P1 with a = 1037.7(3), b = 1153.0(2), c = 1393.8(3) pm, α = 72.31(2)°, β = 74.06(2)°, γ = 67.94(2)°, and Z = 1. The bond lengths of the Re–N triple bonds are 172 pm in 1 and 170 pm in 1 · 2 SbCl₃. By the reaction of ReNCl₂(PMePh)₃ with SbCl₅ in CH₂Cl₂ the solvent is decomposed forming HCl which protonates the nitrido ligand to afford the imido complex [Re(NH)Cl₂(PMe₂Ph)₃][SbCl₆] ( 2 ) crystallizing in the monoclinic space group P2₁/n with a = 1221.4(2), b = 1358.6(2), c = 2177.3(1) pm, β = 92,72(1)° and Z = 4. The Re–N distance in the almost linear unit Re≡N–H is 169,1 pm.     

Synthese,Struktur und Eigenschaften der Komplexe [(H2O)Cl4Os≡N‐IrCl(C5Me5)(AsPh3)], [(Ph3Sb)Cl4Os≡N‐IrCl(C5Me5)(SbPh3)], [(Ph3Sb)2Cl3Os≡N‐IrCl(COD)] und [{(Me2PhP)2(CO)Cl2Re≡N}2ReNCl2(PMe2Ph)]

Synthesis, Crystal Structure, and Properties of the Complexes [(H₂O)Cl₄Os≡N‐IrCl(C₅Me₅)(AsPh₃)], [(Ph₃Sb)Cl₄Os≡N‐IrCl(C₅Me₅)(SbPh₃)], [(Ph₃Sb)₂Cl₃Os≡N‐IrCl(COD)] and [{(Me₂PhP)₂(CO)Cl₂Re≡N}₂ReNCl₂(PMe₂Ph)] The dinuclear complexes [(H₂O)Cl₄Os≡N‐IrCl(C₅Me₅)(AsPh₃)]·H₂O ( 1 ·H₂O), [(Ph₃Sb)Cl₄Os≡N‐IrCl(C₅Me₅)(SbPh₃)] ( 2 ), and [(Ph₃Sb)₂Cl₃Os≡N‐IrCl(COD)] ( 3 ) result from the reaction of the nitrido complexes [(Ph₃As)₂OsNCl₃] and [(Ph₃Sb)₂OsNCl₃] with the iridium compounds [IrCl₂(C₅Me₅)]₂ and [IrCl(COD)]₂ in dichloromethane. 1 crystallizes as 1 ·H₂O in form of green platelets in the monoclinic space group Cm and a = 1105.53(6); b = 1486.76(9); c = 2024.88(10) pm, β = 97.191(4)°, Z = 4. The formation of 1 in air involves a ligand exchange, and the coordination of a water molecule in trans position to the Os‐N triple bond. The resulting complex fragments [(H₂O)Cl₄Os≡N] and [IrCl(C₅Me₅)(AsPh₃)] are connected by an asymmetric nitrido bridge Os≡N‐Ir. The nitrido bridge is characterised by an Os‐N‐Ir bond angle of 173.7(7)°, and distances Os‐N = 168(1) pm and Ir‐N = 191(1) pm. 2 crystallizes in clumped together brown platelets with the space group and a = 1023.3(3), b = 1476.2(3), c = 1872.5(6) pm, α = 74.60(2), β = 73.84(2), γ = 76.19(2)°, Z = 2. In 2 the asymmetric nitrido bridge Os≡N‐Ir joins the two complex fragments [(Ph₃Sb)Cl₄Os≡N] and [IrCl(C₅Me₅)(SbPh₃)], which are formed by a ligand exchange reaction. 3 forms dark green crystals with the triclinic space group and a = 1079.4(1), b = 1172.3(1), c = 1696.7(2) pm, α = 101.192(9),β = 92.70(1), γ = 92.61(1)°, Z = 2. The distances in the almost linear nitrido bridge (Os≡N‐Ir = 175.3(7)°) are Os‐N = 171(1) pm and Ir‐N = 183(1) pm. The reaction of [ReNCl₂(PMe₂Ph)₃] with [Mo(CO)₃(NCMe)₃] unexpectedly affords the trinuclear complex [{(Me₂PhP)₂(OC)Cl₂Re≡N}₂ReNCl₂(PMe₂Ph)] ( 4 ) as the main product. It forms triclinic brown crystals with the composition 4 ·2THF and the space group (a = 1382.70(7), b = 1498.58(7), c = 1760.4(1) pm, α = 99.780(7), β = 99.920(7), γ = 114.064(6)°, Z = 2). In the trinuclear complex, the central fragment, [ReNCl₂(PMe₂Ph)] is joined in trans position to two nitrido complexes [(Me₂PhP)₂(CO)Cl₂Re≡N], giving an almost linear Re≡N‐Re‐N≡Re arrangement. The bond angles and distances in the nitrido bridges are Re‐N‐Re = 167.8(3)°, Re‐N = 171.1(8) pm and 204.2(8) pm; and Re‐N‐Re = 168.1(4)°, Re‐N = 170.9(9) and 203.5(9) pm respectively. As expected, the Re‐N bond length to the terminal nitrido ligand on the central Re atom is much shorter at 161.2(9) pm than the triple bonds of the asymmetric bridges.     

Synthese und Kristallstrukturen der heteronuklearen Nitrido‐Komplexe [(Me2PhP)3(MeCN)ClRe≡N–MCl5] mit M = Sn und Zr

Synthesis and Structures of the Dinuclear Nitrido Complexes [(Me₂PhP)₃(MeCN)ClRe≡N–MCl₅] with M = Sn and Zr The water sensitive complexes [(Me₂PhP)₃(MeCN)ClRe≡N–MCl₅] (M = Sn ( 1 ) und Zr ( 2 )) are obtained in dichloromethane from [ReNCl₂(PMe₂Ph)₃] and the acetonitrile adducts of SnCl₄ or ZrCl₄. The compounds crystallize as dichloromethane solvate isotypically with [(Me₂PhP)₃(MeCN)ClRe≡N–TiCl₅] · CH₂Cl₂ in the space group P2₁/n. From toluene crystallize monoclinic crystals of 1 · MeCN · C₇H₈. In the diamagnetic complexes 1 and 2 an anion [MCl₅]^– coordinates to the nitrido ligand of the cationic complex [ReNCl(MeCN)(PMe₂Ph)₃]⁺. The resulting nitrido bridges Re≡N–M are almost linear and asymmetric with Re–N = 169.5 pm, Sn–N = 230.1 pm and Re–N–Sn = 164.5° for 1 and Re–N = 168.4 pm, Zr–N = 237.2 pm and Re–N–Zr = 165.6° for 2 . The phosphine ligands at the Re atom are in a meridional arrangement.     

Darstellung von Organylquecksilber(II)‐di(methansulfonyl)amiden und Kristallstruktur von Ph–Hg–N(SO2Me)2

Polysulfonylamines. CXXIV. Preparation of Organylmercury(II) Di(methanesulfonyl)amides and Crystal Structure of Ph–Hg–N(SO₂Me)₂ Four N,N‐disulfonylated organylmercury(II) amides R–Hg–N(SO₂Me)₂, where R is Me, ⁱPr, Me₃SiCH₂ or Ph, were obtained on treating the appropriate chlorides RHgCl with AgN(SO₂Me)₂, and characterized by ¹H and ¹³C NMR spectra. In the crystal structure of the phenyl compound (orthorhombic, space group Pbca, Z = 8, X‐ray diffraction at –95 °C), the molecule exhibits a covalent and significantly bent C–Hg–N grouping [bond angle 172.7(3)°; Hg–C 204.0(8), Hg–N 209.1(7) pm]. One sulfonyl oxygen atom forms a short intramolecular Hg…O contact [296.1(5) pm] and simultaneously catenates glide‐plane related molecules via a second Hg…O interaction 297.6(5) pm], thus conferring upon Hg^II the effective coordination number 4 and a geometrically irregular coordination polyhedron (bond angles from 173 to 54°).     

Nitridorhenium(V)‐Komplexe mit Dimercaptobernsteinsäuredimethylester. Präparation,Charakterisierung und Kristallstruktur von [Re{NC(CH3)2PPhMe2}(DMSMe2)2]

Nitridorhenium(V) Complexes with Dimercapto Succinic Acid Dimethylester. Preparation, Characterization, and Crystal Structure of [Re{NC(CH₃)₂PPhMe₂}(DMSMe₂)₂] Reaction of [ReNCl₂(Me₂PhP)₃] 1 with two equivalents of dimercaptosuccinic acid dimethylester (DMSMe₂) results in the formation of a neutral, diamagnetic rhenium(V)‐DMSMe₂ complex with a phenyldimethylphosphinoisopropyl group at the nitrido ligand as a consequence of a nucleophilic attack of the coordinated nitrido ligand on the solvent molecule. The formed complex 2 of the composition [Re{NC(CH₃)₂(Me₂PhP)}(DMSMe₂)₂] crystallizes in the triclinic space group P 1, a = 12.334(7), b = 12.412(7), c = 12.414(8) Å; α = 60.14(3)°, β = 67.98(3)°, γ = 80.63(6)°; Z = 2. Rhenium is located in a square‐pyramidal configuration of the donor atoms. The two meso‐DMSMe₂ ligands are in a syn‐endo conformation. The rhenium‐nitrogen bond (1.697(12) Å) is only slightly longer than typical Re–N bonding distances in nitrido complexes and comparable with other Re–N–C bonding distances. The addition of a solvent molecule is observed in acetone ( 2 ) as well as in methylethylketone ( 3 ). Moreover, a reaction of the nitrido group with the condensation product of ketone is found by mass spectrometry ([ReN{C(CH₃)(C₂H₅)CH₂C(O)C₂H₅(Me₂PhP)}(DMSMe₂)₂] 4 ).     

Nitridorhenium(V) Complexes with 1,3,4‐Triphenyl‐1,2,4‐triazol‐5‐ylidene

[ReNCl₂(PPh₃)₂] and [ReNCl₂(PMe₂Ph)₃] react with the N‐heterocyclic carbene (NHC) 1,3,4‐triphenyl‐1,2,4‐triazol‐5‐ylidene (HL^Ph) under formation of the stable rhenium(V) nitrido complex [ReNCl(HL^Ph)(L^Ph)], which contains one of the two NHC ligands with an additional orthometallation. The rhenium atom in the product is five‐coordinate with a distorted square‐pyramidal coordination sphere. The position trans to the nitrido ligand is blocked by one phenyl ring of the monodentate HL^Ph ligand. The Re–C(carbene) bond lengths of 2.072(6) and 2.074(6) Å are comparably long and indicate mainly σ‐bonding between the NHC ligand and the electron deficient d² metal atom. The chloro ligand in [ReNCl(HL^Ph)(L^Ph)] is labile and can be replaced by ligands such as pseudohalides or monoanionic thiolates such as diphenyldithiophosphinate (Ph₂PS₂^?) or pyridine‐2‐thiolate (pyS^?). X‐ray structure analyses of [ReN(CN)(HL^Ph)(L^Ph)] and [ReN(pyS)(HL^Ph)(L^Ph)] show that the bonding situation of the NHC ligands (Re–C(carbene) distances between 2.086(3) and 2.130(3) Å) in the product is not significantly influenced by the ligand exchange. The potentially bidentate pyS^? ligand is solely coordinated via its thiolato functionality. Hydrogen atoms of each one of the phenyl rings come close to the unoccupied sixth coordination positions of the rhenium atoms in the solid state structures of all complexes. Re–H distances between 2.620 and 2.712Å do not allow to discuss bonding, but with respect to the strong trans labilising influence of “N^3?”, weak interactions are indicated.     

Reactions of Rhenium and Technetium Nitrido Complexes with ER3 Fragments (E = B,Ga, Al,C, P; R = H,Alkyl, Aryl)

Terminal ‘N^3—’ ligands in rhenium and technetium nitrido complexes are sufficiently nucleophilic to react with Lewis acids under formation of nitrido‐bridged compounds. The reactivity of the nucleophilic centre and the nature of the formed compounds are strongly dependent on the Lewis acid and the composition of the metal complex used. Air‐stable compounds with Re≡N‐ER₃ bridges are formed when ER₃ is BR₃ (R = H, Cl, Br, Ethyl, Phenyl, C₆F₅), BCl₂Ph, GaCl₃, CPh₃⁺, or PPh₃. The six‐co‐ordinate rhenium(V) complexes [ReNX₂(PMe₂Ph)₃] (X = Cl, Br), [ReN(X)(Et₂dtc)(PMe₂Ph)₂] (Et₂dtc^— = diethyldithiocarbamate) and [ReN(Et₂dtc)₂(PMe₂Ph)] have been proved to be excellent starting materials for this type of reactions, whereas the five‐co‐ordinate precursors [ReNCl₂(PPh₃)₂], [ReN(Et₂dtc)₂], [ReN{Ph₂P(S)NP(S)Ph₂}₂] or [ReNCl₄]^— only react with the most reactive Lewis bases of the examples mentioned above such as BCl₂Ph or B(C₆F₅)₃. The rhenium‐nitrido bond lengths remain almost unchanged by the adduct formation, whereas a significant decrease of the trans‐influence of the nitrido complexes has been observed as can be seen by a shortening of the corresponding bond lengths or dimerization of five‐co‐ordinate precursors. Electrophilic attack of the Lewis acid to a donor atom of the equatorial co‐ordination sphere of the rhenium complex results in the formation of ‘underco‐ordinate’ metal centres which resemble to di‐, tri or tetrameric units with asymmetric nitrido bridges between each two rhenium atoms. EPR spectroscopy is an excellent tool to reflect the formation of nitrido bridges at the paramagnetic (d¹) [ReNX₄]^— core (X = F, Cl, Br, NCS). The spectral parameters derived for the products of reactions of [ReNCl₄]^— with various boron compounds indicate an increase of the covalency of the equatorial Re‐L bonds as a consequence of the formation of a nitrido bridge. The tendency for the formation of nitrido bridges with Lewis acids is significantly lower for technetium compounds compared to their rhenium analogues. Only a few examples with BH₃ and BPhCl₂ have been established.     

Synthese,Kristallstruktur und Eigenschaften von Tetranatrium‐bis(trimetaphosphimato)cuprat(II)‐Decahydrat,Na4{Cu[(PO2NH)3]2} · 10 H2O

Synthesis, Crystal Structure, and Properties of Tetrasodium Bis(trimetaphosphimato)cuprate(II) Decahydrate, Na₄{Cu[(PO₂NH)₃]₂} · 10 H₂O Tetrasodium bis(trimetaphosphimato)cuprate(II) decahydrate, Na₄{Cu[(PO₂NH)₃]₂} · 10 H₂O, was obtained by the reaction of an aqueous solution of Na₃(PO₂NH)₃ · 4 H₂O with Cu(NO₃)₂ · 3 H₂O (molar ratio 2 : 1). The structure of Na₄{Cu[(PO₂NH)₃]₂} · 10 H₂O ( 1 ) was solved by single‐crystal X‐ray methods (P 1, a = 912.51(6), b = 932.14(6), c = 966.10(6) pm, α = 94.840(5), β = 108.652(6), γ = 118.588(6)°, Z = 1). The P₃N₃ rings of the trimetaphosphimate ions exhibit a slightly distorted sofa conformation. The conformation of the anions have been analysed using torsion angles, displacement asymmetry parameters, and puckering parameters. The trimetaphosphimate ions act as bidentate ligands of Cu²⁺. With additionally coordinated water molecules, anionic complexes {Cu[(PO₂NH)₃]₂ · 2 H₂O}^4– are formed. In the crystal these complexes are interconnected by N–H…O und O–H…O hydrogen bonds and they coordinate the Na⁺. Thus, a three‐dimensional network is formed.     

Gemischtligandkomplexe des Rheniums. V. Die Bildung von Nitrenkomplexen durch Kondensation von Aceton an koordinierten Nitridoliganden. Darstellung und Strukturen von fac-[Re{NC(CH3)2CH2C(O)CH3}X3(Me2PhP)2]-Komplexen (X = Cl,Br)

Mixed-ligand Complexes of Rhenium. V. The Formation of Nitrene Complexes by Condensation of Acetone at Coordinated Nitrido Ligands. Syntheses and Structures of fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}X₃(Me₂PhP)₂] Complexes (X = Cl, Br) The reaction of rhenium(V)-mixed-ligand complexes of the general formula [ReN(Cl)(Me₂PhP)₂(R₂tcb)] (HR₂tcb = N? (N,N-dialkylthiocarbamoyl)benzamidine) with HCl or HBr in acetone initializes a condensation of the solvent and results in nitrene-like compounds as a consequence of a nucleophilic attack of the coordinated nitrido ligand on the condensed acetone. The chelate ligands are removed during this reaction and complexes of the type fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}X₃(Me₂PhP)₂] (X = Cl, Br) are formed. fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}Cl₃(Me₂PhP)₂] crystallizes triclinic in the space group P1, a = 8.575(4); b = 9.088(3); c = 18.389(9) Å; α = 75.67(3)°, β = 85.30(3)°, γ = 70.58(4)°; Z = 2. A final R value of 0.031 was obtained on the basis of 6011 independent reflections with I ≥ 2σ(I). Rhenium is coordinated in a distorted octahedral environment with the three chloro ligands in facial positions. The rhenium-nitrogen bond (1,68(1) Å) is only slightly longer than typical Re? N bonding distances in nitrido complexes. fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}Br₃(Me₂PhP)₂] is isomorphous with the chloro complex. Triclinic cell with a = 8.625(4); b = 9.198(3); c = 18.581(5) Å; α = 75.62(3)°, β = 85.40(3)°, γ = 70.91(3)°; Z = 2. The R value converged at 0.049 on the basis of 3644 independent reflections with I ≥ 2σ(I). fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}Cl₃(Me₂PhP)₂] as well as fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}Br₃(Me₂PhP)₂] crystallizes in the noncentrosymmetric space group P1.     

Synthese und Struktur der Komplexe [(Me2PhP)3Cl2Re≡N‐RuCl2(C6H6)] und [(Me2PhP)3Cl2Re≡N‐RhCl(COD)]

Synthesis and Crystal Structure of the Complexes [(Me₂PhP)₃Cl₂Re≡N‐RuCl₂(C₆H₆)] and [(Me₂PhP)₃Cl₂Re≡N‐RhCl(COD)] The heteronuclear complex [(Me₂PhP)₃Cl₂Re≡N‐RuCl₂(C₆H₆)] ( 1 ) is obtained by the reaction of [ReNCl₂(PMe₂Ph)₃] with [RuCl₂(C₆H₆)]₂ in C₆H₅CN in form of red crystals with the composition 1 ·C₆H₅CN crystallizing in the monoclinic space group P2₁/c with a =1149.77(8), b = 3085.9(3), c = 1172.1(1) pm, β = 104.766(9)° and Z = 4. In the dinuclear complex the complex fragment [RuCl₂(C₆H₆)] is connected by an asymmetric nitrido bridge with the nitrido complex [ReNCl₂(PMe₂Ph)₃]. The nitrido bridge is characterised by a bond angle Re‐N‐Ru of 170.6(3)° and distances Re‐N = 170.2(5) and Ru‐N = 199.0(5) pm. The reaction of [ReNCl₂(PMe₂Ph)₃] with [RhCl(COD)]₂ in benzonitrile yields orange crystals of [(Me₂PhP)₃Cl₂Re≡N‐RhCl(COD)] ( 2 ) with the space group P2₁/c and a = 1522.3(2), b = 1274.85(4), c = 1921.2(2) pm, β = 106.759(7)° and Z = 4. The monovalent Rh atom exhibits a square planar coordination with the two π‐bonds of the cycloocta‐1, 5‐diene occupying cis positions. The distances in the almost linear nitrido bridge (Re‐N‐Rh = 174.8(4)°>) are Re‐N = 172.2(6) pm and Rh‐N = 195.6(6) pm.     

Koordinationseigenschaften der isolobalen Phosphaniminatound Cyclopentadienyl‐Liganden in TiCl3(NPH3), TiCl3Cp,ReO3(NPH3) und ReO3Cp

Coordination Behaviour of the Isolobal Phosphoraneiminato and Cyclopentadienyl Ligands in TiCl₃(NPH₃), TiCl₃Cp, ReO₃(NPH₃), and ReO₃Cp The phosphoraneiminato and cyclopentadienyl complexes TiCl₃(NPH₃) ( 1 ), ReO₃(NPH₃) ( 2 ), TiCl₃Cp ( 3 ), and ReO₃Cp ( 4 ) have been investigated quantum chemically at the BP86/TZ(2)P level of nonlocal density functional theory (DFT). The metal–ligand bonds turn out to dissociate homolytically with the computed values for the corresponding bond dissociation energies amounting to 79.6 ( 1 ), 103.4 ( 2 ), 58.1 ( 3 ) and 45.0 ( 4 ) kcal/mol. Whereas the M–N–P unit in the titanium complex 1 is linear, we find a bent structure for the corresponding rhenium complex 2 (∠ Re–N–P = 136.4°). It turns out that the potential energy surface of the phosphoraneiminato complexes is extremely shallow with respect to the M–N–P angle; a variation over 50° is associated with an energy change of less than 2 kcal/mol. Furthermore, we have carried out a detailed analysis of the bonding in our model complexes to elucidate the difference in metal–ligand bond strengths between the isolobal phosphoraneiminato and cyclopentadienyl ligands.     

Komplexchemie P‐reicher Phosphane und Silylphosphane. XXII. Die Bildung von [η2‐{tBu–P=P–SiMe3}Pt(PR3)2]aus (Me3Si)tBuP–P=P(Me)tBu2 und [η2‐{C2H4}Pt(PR3)2]

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XXII. The Formation of [η²‐{^tBu–P=P–SiMe₃}Pt(PR₃)₂] from (Me₃Si)^tBuP–P=P(Me)^tBu₂ and [η²‐{C₂H₄}Pt(PR₃)₂] (Me₃Si)^tBuP–P = P(Me)^tBu₂ reacts with [η²‐{C₂H₄}Pt(PR₃)₂] yielding [η²‐{^tBu–P=P–SiMe₃}Pt(PR₃)₂]. However, there is no indication for an isomer which would be the analogue to the well known [η²‐{^tBu₂P–P}Pt(PPh₃)₂]. The syntheses and NMR data of [η²‐{^tBu–P=P–SiMe₃}Pt(PPh₃)₂] and [η²‐{^tBu–P=P–SiMe₃}Pt(PMe₃)₂] as well as the results of the single crystal structure determination of [η²‐{^tBu–P=P–SiMe₃}Pt(PPh₃)₂] are reported.