Komplexchemie P-reicher Phosphane und Silylphosphane. IV. Bildung und Struktur der Chromcarbonylkomplexe des Tris(di-tert-butylphospha)heptaphosphanortricyclans, (t-Bu2P)3P7

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. IV. Formation and Structure of the Chromium Carbonyl Complexes of Tris(di-tert-butylphospha)heptaphosphanortricyclane (t-Bu₂P)₃P₇ The reaction of (t-Bu₂P)₃P₇ 1 with Cr(CO)₅ · THF in a molar ratio of 1:1 yields yellow crystals of (t-Bu₂P)₃P₇[Cr(CO)₅] 2 having the Cr(CO)₅ group coordinated to a P^b atom (basal) of the three membered ring. With a molar ratio of 1:2 compounds 2 , (t-Bu₂P)₃P₇[Cr(CO)₅]₂ 3 , (t-Bu₂P)₃P₇[Cr(CO)₅][Cr(CO)₄] 4 and (t-Bu₂P)₃P₇[Cr(CO)₄]₂ 5 were obtained. In 3 (yellow crystals) one Cr(CO)₅ group is linked to a P^b atom, the other one to an exocyclic P^exo atom. On irradiation 3 loosing one CO group generates 4 (orange red crystals) with an unchanged Cr(CO)₅ group linked to the Pb atom and a five membered chelate-like ring containing an apical Pa atom, two equatorial P^a atoms, one P^exo atom and the Cr atom of the carbonyl group. Compound 5 (orange red crystals) contains two such five membered rings. (t-Bu₂P)₃P₇[Cr(CO)₄]₃ 6 (red needles) is formed with Cr(CO)₅ · THF in a molar ratio of 1 : 1. However, even with higher amounts of Cr(CO)₅ · THF and after extended reaction times, only 6 is formed; no further Cr carbonyl group could be attached to the P skeleton. With Cr(CO)₅ · NBD in a molar ratio of 1 : 1, (t-Bu₂P)₃P₇[Cr(CO)₄] 7 is produced from 1, and 5 with a molar ratio of 2 : 1. As in 4, the Cr(CO)₄ group in 7 (orange crystals) participates in a five membered chelate-like ring. It was not possible to generate 6 from 5 with an excess of Cr(CO)₄ · NBD and with extended reaction times. The molecular structures of the compounds were identified by investigating the ³¹P[¹H] NMR spec-tra and considering especially the coordination shift, and by crystal structure determinations of 2 and 4. Compound 2 crystallizes in the space group PI (no.2) with a = 1566.2(4) pm, b = 2304.1(5) pm, c = 1563.3(4) pm,α = 95.57(3)°, β = 108.79(3)°, γ = 109.82(4)° and Z = 4 formula units in the elementary cell. Compound 4 crystallizes in the space group P 2₁ /n (no. 14) with a = 1416.6(5) pm, b = 2573.6(5) pm, c = 1352.9(4) pm,β = 99.17(5)° and Z = 4 formula units in the elementary cell.     

Komplexchemie at P-reicher Phosphane und Silylphosphane. VI. Bildung und Struktur der Chromcarbonylkomplexe des Tris(trimethylsilyl) heptaphosphanortricyclans (Me3Si)3P7

Formation and Structures of Chromium Carbonyl Complexes of Tris(trimethylsily)heptanortricyclane (Me₃Si)₃P₇ (Me₃Si)₃P₇ 1 reacts with one equivalent of Cr(Co)₅THF 2 to give the yellow (Me₃Si)₃P₇[Cr(Co)₅] 4. The Cr(Co)₅group is attached to a P^e atom. Yellow (Me₃Si)₃P₇[Cr(CO)₅]₂ 5 is obtained either from reacting 1 with two equivalents of 2 , or from 4 with one equivalent of 2. One Cr(CO)₅ groups in 5 is coordinated to a P^e atom, the other one to a P,^b atom. Similarly, Yellow (Me₃Si)₃P₇[Cr(CO)₅]₃ 6 results from reacting 5 with one equivalent of 2 . Two Cr(CO)₅ groups in 6 are linked to P^b atoms, and the third one either to a P^e or the P^a atom (assignment not completely clear). Derivatives containing a P^e bridge appear in reactions of 1 with higher amounts of 2 . Such, 5 forms mixtures of the red compounds (Me₃Si)₃P₇ × [Cr(CO)₅]₂[Cr(CO)₄] 8 and (Me₃Si)₃P₇[Cr(CO)₅] × [Cr(CO)₄] 9 , and even preferably 9 with four equivalents of 2 . In 8 , one Cr(CO)₅ group is attached to that p^e atom which is not engaged in the Cr(CO)₄ bridge, and the second to one of the P^b atoms directly adjacent to the bridge. The additional Cr(CO)₅ group in 9 is coordinated to the remaining P^b atom directly adjacent to the bridge. In reactions of 5 with even higher amounts of 2 , four Cr(CO)₅ groups and one Cr(CO)₄ bridge attach to the basic P₇ skeleton to from the less stable Me₃P₇[Cr(CO)₅]₄[Cr(CO)₄]. (Me₃Si)₃P₇ 1 reacts considerably slower with Cr(CO)₅THF 2 than R₃P₇ (R = Et, iPr). Cr(CO)₄NBD 3 reacts with 1 , but it was not possible to isolate (Me₃Si)₃P₇[Cr(CO)₄]. However, 4 with 3 forms (Me₃Si)₃P₇[Cr(CO)₅][Cr(CO)₄] 7 , and 5 with 3 yields (Me₃Si)₃P₇[Cr(CO)₅]₂[Cr(CO)₄] 8 . The structures of 4 , 5 , 7 , 8 or 9 are quite analogous to those of the derivatives of Et₃P₇ but there exist significant differences in stability and reactivity. While Et₃P₇[Cr(CO)₅]₂ in solution rearranges to give the stable Et₃P₇[Cr(CO)₅][Cr(CO)₄], the analogous (Me₃Si)₃P₇[Cr(CO)₅][Cr(CO)₄] 7 is not stable and is not obtained from (Me₃Si)₃P₇[Cr(CO)₅]₂ 5 . Et₃P₇[Cr(CO)5]₃ can just be detected spectroscopically and rearranges easily to give Et₃P₇[Cr(CO)₅]₂ [Cr(CO)₄] whereas (Me₃Si)₃P₇[Cr(CO)₅]₃ 6 can be isolated. These differences are caused by the greater steric requirements of Me₃Si groups. The formation of a P^e–Cr(CO)₄–P^e bridge, e.g., requires a Me₃Si group in 1 to switch from the s to the as position. Whereas many of the complex compounds of R₃P₇ (R = Et, iPr) crystallize easily, the analogous derivatives of (Me₃Si)₃P₇ did not yield crystals. The structures of the products were assigned by evaluating the coordination shift in their ₃₁P NMR spectra and by comparision of these spectra with those of such derivatives of Et₃P₇ which previously had been investigated by single crystal structure determinations.     

Komplexchemie P-reicher Phosphane und Silylphosphane. VII. Carbonylkomplexe des Heptaphosphans(3) iPr2(Me3Si)P7

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. VII Carbonyl Complexes of the Heptaphosphane(3) iPr₂(Me₃Si)P₇ From the reaction of iPr₂(Me₃Si)P₇ 1 with one equivalent of Cr(CO)₅THF the yellow products iPr₂(H)P₇[Cr(CO)₅] 2 and iPr₂(Me₃Si)P₇[Cr(CO)₅] 3 were isolated by column chromatography on silicagel. The P? H group in 2 results from a cleavage of the P? SiMe₃ bond during chromatography. The Cr(CO)₅ group in 2 is linked to an iPr? P^e atom, in 3 to the Me₃Si? P^e atom of the P₇ skeleton. The substituents do not force the formation of a single isomer; nevertheless 3 ist considerably favoured as compared to 2 . From the reaction of 1 with 2 equivalents of Cr(CO)₅THF the yellow iPr₂(H)P₇[Cr(CO)₅]₂ 4 was isolated bearing one Cr(CO)₅ group at an iPr? P^e atom, the other one at a P^b atom of the P₇ skeleton. Compound 3 yields with Cr(CO)₄NBD the red iPr₂(Me₃Si)P₇[Cr(CO)₅][Cr(CO)₄] 5 . Three isomers of 5 appear. Two P^e atoms of 5 are bridged by the Cr(CO)₄ group, the third P^e atom is linked to the Cr(CO)₅ ligand. iPr₂(H)P₇[Fe(CO)₄] was isolated from the reaction of 1 with Fe₂(CO)₉. ³¹P NMR and MS data are reported.     

Komplexchemie P-reicher Phosphane und Silylphosphane. X [1] Zum Einfluß der Komplexierung auf die Reaktivität des [(Me3Si)2P]2PH

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. X. The Influence of the Formation of Complex Compounds on the Reactivity of [(Me₃Si)₂P]₂PH Whereas [(Me₃Si)₂P]₂PH 1 by BuLi is attacked at the PH group to give [(Me₃Si)₂P]₂PLi 2 , the related chromium carbonyl complex (Me₃Si)P^IV ? ²P^IV(H) ? ³P^III(Si? Me₃)₂ · Cr(CO)₄ 3 with BuLi yields Li(Me₃Si)¹P^IV ? ²P^IV(H) ? ³P^III(SiMe₃)₂ · Cr(CO)₄ 4 by cleaving a Si? P bond at the chromium substituted ¹P atom. Dissolved in ether, 4 is stable for a longer time, while under comparable conditions 2 forms Li₃P₇ which is not obtained from 4 . MeOH in 3 cleaves selectively the Me₃Si groups from the complex substituted P atom yielding (Me₃Si)(H)¹P^IV ? ²P^IV(H) ? ³P^III(SiMe₃)₂ · Cr(CO)₄ 5 and HP^IV ? ²P^IV(H) ? ³P^III(SiMe₃)₂Cr(CO)₄ 6. 5 and 6 seem to be stable in contrast to the uncoordinated triphosphanes which are not known.     

Komplexchemie P‐reicher Phosphane und Silylphosphane. XXV. Bildung und Struktur des [{cyclo‐P3(PtBu2)3}{Ni(CO)2}{Ni(CO)3}]

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XXV. Formation and Structure of [{ cyclo ‐P₃(P^tBu₂)₃}{Ni(CO)₂}{Ni(CO)₃}] ^tBu₂P–P=P(R)^tBu₂ (R = Br, Me) reacts with [Ni(CO)₄] yielding [{cyclo‐P₃(P^tBu₂)₃}{Ni(CO)₂}{Ni(CO)₃}]. The two cis‐^tBu₂P substituents of the cyclotriphosphane, which results from the trimerization of the phosphinophosphinidene ^tBu₂P–P, are coordinating to a Ni(CO)₂ unit forming a five‐membered P₄Ni chelate ring. The trans‐^tBu₂P group is linked to a Ni(CO)₃ unit. The compound crystallizes in the orthorhombic space group Pbca (No. 61) with a = 933.30(5), b = 2353.2(1) and c = 3474.7(3) pm.     

Reaktionen von Nitrosylkomplexen. XIII. Synthese neuer zwei- und dreikerniger heterobimetallischer Komplexe mit NO-Brückenliganden

Reactions of Nitrosyl Complexes. XIII. Synthesis of Novel Di- and Trinuclear Heterobimetallic Complexes with Bridging NO Ligands By reaction of [{Cp′Fe(μ-NO)}₂] with [Cp′Mn(CO)₂ · (THF)] (Cp′ = μ⁵-C₅H₄Me) in THF [Cp₃′Fe₂Mn(μ-CO)₂(μ-NO) · (μ₃-NO)] 1 is formed in high yield. The reaction of [{Cp′Fe(μ-NO)}₂]Na with [Cp′Mn(CO)₂NO]BF₄ in DME/acetone yields besides known [{Cp′Mn(CO)(NO)}₂] 2 the novel complex [Cp₂′FeMn(μ-NO)₂NO] 3 . By interaction between [Cp′Mn(CO)₂(THF)] and 3 , [Cp₃′FeMn₂(μ-CO)(μ-NO)₂ · (μ₃-NO)] 4 is formed. The complex 4 represents the hitherto unknown missing link in the series of the isoelectronic clusters [Cp₃′Mn₃(μ-NO)₃(μ₃-NO)], 1 , and [Cp₃′Fe₃(μ-CO)₃(μ₃-NO)]. Attempts to synthesize the unknown complex [(Cp′FeNO)₂ · Cr(CO)₅] by addition of carbene analogous Cr(CO)₅ fragments to the Fe=Fe bond in [{Cp′Fe(μ-NO)}₂] only led to very low yields of [Cp₂′FeCr(CO)₅] 5 . The new complexes were characterized by mass, NMR and IR spectra.     

Dimethyl(tetramethylcyclopentadienyl)silyl-, -germyl- und -stannyl-phosphane. Röntgenstrukturanalyse von Chloro(dimethyl)tetramethylcyclopentadienylstannan und Tetracarbonyl[1-dimethyl-(tetramethylcyclopentadienyl)germyl-3,4-dimethylphospholen]eisen(0)

Dimethyl(tetramethylcyclopentadienyl)silyl-, -germyl-, and -stannylphosphanes. X-Ray Structures of Chloro(dimethyl)tetramethylcyclopentadienyl-stannane and Tetracarbonyl[1-dimethyl(tetramethylcyclopentadienyl)germyl-3,4-dimethyl-phospholene]iron(0) Me₂Cp′SiCl ( 1 ) (Cp′ = C₅HMe₄) reacts with magnesium and R₂PCl (R = Ph, ^tBu) as well as PCl₃ in tetrahydrofurane yielding Me₂Cp′SiPPh₂ ( 4 ), Me₂Cp′SiP^tBu₂ ( 5 ) and (Me₂Cp′Si)₃P ( 6 ) respectively. The reaction of Me₃SiPPh₂ ( 7 ) or Me₃SiPC₄H₄Me₂ ( 10 ) with Me₂Cp′GeCl ( 2 ) and Me₂Cp′SnCl ( 3 ) leads to the formation of Me₂Cp′EPPh₂ (E = Ge ( 8 ), Sn ( 9 )) and Me₂Cp′EPC₄H₄Me₂ (E = Ge ( 11 ), Sn ( 12 )). 11 reacts with Fe(CO)₅ with formation of Fe(CO)₄[(PC₄H₄Me₂)GeCp′Me₂] ( 13 ). 3 crystallizes in the space group P2₁/n with a = 986,7(1), b = 1247,3(2), c = 1028,2(1) pm, β = 92,71(1)°, Z = 4 and V = 1264,1(2) 10^?30 m³. The final refinement resulted in R₁ = 0,0249 for 2097 observed reflexions with F_o ≥ 4σ(F_o). 13 crystallizes in the space group P2₁/n with a = 967,7(3), b = 1298,70(16), c = 1832,7(3) pm, β = 95,810(19)°, Z = 4 and V = 2291,4(8) 10^?30 m³ (R₁ = 0,0444 for 4043 observed reflexions with F_o ≥ 4σ(F_o). 13 forms a trigonal bipyramide with the phosphane ligand 11 in an axial position.     

Komplexchemie P-reicher Phosphane und Silylphosphane. XI [1]. Bildung,Reaktionen und Strukturen von Chromcarbonylkomplexen aus Reaktionen von Li(THF)2[η2-(tBu2P)2P] mit Cr(CO)5 · THF und Cr(CO)4 · NBD

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. XI. Formation, Reactions, and Structures of Chromium Carbonyl Complexes from Reactions of Li(THF)₂[η₂-(^tBu₂P)₂P] with Cr(CO)₅ · THF and Cr(CO)₄ · NBD Reactions of Li(THF)₂[η²-(^tBu₂P)₂P] 1 with Cr(CO)₅ · THF yield Li(THF)₂Et₂O[Cr(CO)₄{η²-(^tBu₂P)₂P}η¹-Cr(CO)₅] 2 and the compounds [Cr(CO)₄{η²-(^tBu₂P)₂PH}] 3 , [Cr(CO)₅{η¹-(^tBu₂P)₂PH}] 4 , (^tBu₂P)₂PH 5 and ^tBu₂PH · Cr(CO)₅ 6 . The formation of 3, 4, 5 and 6 is due to byproducts coming from the synthesis of 1. 2 reacts with CH₃COOH under formation of 3 . After addition of 12-crown-4 1 with NBD · Cr(CO)₄ in THF forms Li(12-crown-4)₂[Cr(CO)₄-{η²-(^tBu₂P)₂P}] 7 (yellow crystals). 7 reacts with CH₃COOH to 3 – which regenerates 7 with LiBu – with Cr(CO)₅THF to compound 2 , with NBD · Cr(CO)₄ in THF to 2 and 3 (ratio 1 : 1). With EtBr, 7 forms [Cr(CO)₄{η²-(^tBu₂P)₂PEt}] 8 , and [Cr(CO)₄{η²-(^tBu₂P)₂PBr}] 9 with BrCH₂? CH₂Br. The compounds were characterized by means of ¹H, ¹³C, ³¹P, ⁷Li NMR spectroscopy, IR spectroscopy, elementary analysis, mass spectra, and 2, 3 and 4 additionally by means of X-ray diffraction analysis. 2 crystallizes in the space group P1 with 2 formula units in the elementary cell; a = 10.137(9), b = 15.295(12), c = 15.897(14) Å; α = 101.82(7), β = 91.65(7), γ = 98.99(7)°; 3 crystallizes in the space group P2_t/n with 4 molecules in the elementary unit; a = 11.914(6), b = 15.217(10), c = 14.534(10) Å; α = 90, β = 103.56(5), γ = 90°. 4 : space group P1 with 2 molecules in the elementary unit; a = 8.844(4), b = 12.291(6), c = 14.411(7) Å, α = 66.55(2), β = 89.27(2), γ = 71.44(2)°.     

Stereoselektive Bildung von Oxaspiropentanen und Spiropentylketonen. Zur Stereochemie der nucleophilen Substitution am Cyclopropan

Stereoselective Formation of Oxaspiropentanes and of Spiropentyl Ketones. On the Stereochemistry of Nucleophilic Substitution at Cyclopropanes In an intramolecular S_N2-type substitution with formation of the spiro[2.2]-pentane skeleton, the highly strained transition state 2 with one three membered ring in an equatorial/equatorial and one in an apical/equatorial position of a pentacoordinated carbon atom ought to be - at least formally - involved. Yet, several examples of such processes are known. With the endo/exo isomeric bromohydrines 4 and 5 and bromoketones 13 and 14 this reaction is now shown to occur with clean inversion of configuration at the cyclopropane carbon atom. Unambiguous configurational assignments are made by X-ray crystal structure determinations of the 7′exo-bromo-benzoate 6 (from the bromohydrine 4 ), of the endo-sulfonate 12 (from oxaspiropentane 7 , formed from 4 ), of the 7exo-bromonorcarane 13 , and of its cyclization product 15 . - A comparison of the qualitatively measured rates of epoxide ring formation from the closely related systems 18 and 20 proves the expected slower substitution at the cyclopropane carbon atom as compared to the open chain analogue.     

Bildung von Chelat-Liganden aus Pseudohalogenid und Pyrazol in der Koordinationssphäre von PdII und PtII

Formation of Chelate Ligands from Pseudohalide and Pyrazole in the Coordination Sphere of Pd^II and Pt^II New Pd^II and Pt^II complexes of the composition M(L · X)₂ were prepared (X = NCO^?), N(CN), C(CN), L = pyrazole (Pz), 3, 5-dimethylpyrazole (Dmpz) and studied applying IR spectroscopy. The complexes are obtained by nucleophilic addition of imine nitrogen from the pyrazole ring to the carbon from the pseudohalide anion. When the neutral ligand was Dmpz the reaction ran partially anly. With NCS^? and pz only the complex Cu(NCS)₂(Pz)₂ is yield.     

Komplexchemie P-reicher Phosphane und Silylphosphane. XIII [1]. [η2-{tBu2P?PPtBu2} PtBr(PPh3)]

Coordination Chemistry of P-rich Phosphanes and Silylphosphanes. XIII [1]. [η²-{^tBu₂P? P?P^tBu²} PtBr(PPh₃)] [η²-{^tBu₂P? P?P^tBu₂} PtBr(PPh₃)] 1 is the first transition metal complex compound resulting from a phosphino-phosphinidene-phosphorane. The yellow crystals of 1 (fp. 201–203°C, decomp.) were obtained by reacting ^tBu₂P? P?P(Br)^tBu₂ with either (Ph₃P)₂Pt · C₂H₄, or with Pt(PPh₃)₄, resp. Compound 1 crystallizes triclinic in the space group P1 (no. 2) with a = 1076.80(8) pm, b = 1344.61(8) pm, c = 1381.16(9) pm, α = 81.773(6)°, β; = 85,110(8), γ = 88,776(7).     

Komplexchemie P-reicher Phosphane und Silylphosphane. VII [1]. Bildung und Struktur von [Li(DME)3]2{(SiMe3)[Cr(CO)5]2 P?PP?P[Cr(CO)5]2(SiMe3)}

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. VII. Formation and Structure of [Li(DME)₃]₂{(SiMe₃)[Cr(CO)₅]₂ P-P ? P-P[Cr(CO)₅]₂(SiMe₃)} Deep red crystals of the title compound 1 are produced in the reaction of LiP(Me₃Si)₂[Cr(CO)₅] with 1, 2-dibromoethane in DME. The structure of 1 was derived from the investigation of the ³¹P-NMR spectra and confirmed by a single crystal structure determination. 1 crystallizes in the space group P1 (no. 2); a = 1307.8(5)pm, b = 1373.1(5)pm, c = 1236.1(4)pm, α = 106.22(4)°, β = 88.00(3)°, γ = 115.52(4)° and Z = 1. 1 forms a salt composed of a dianion R₂R₄′P₄^2? (R ? SiMe₃, R′ ? Cr(CO)₅) and solvated Li⁺ cations. The zigzag shaped dianion possesses the symmetry 1 -C_i. The distances d(P? P) = 202.5(1)pm and d(P? P) = 221.9(1)pm correspond to a double bond and single bonds, respectively. The distances d(Cr? P) = 251.1(1) pm and 255.3(1) pm are larger than those observed so far which might be caused by the charge distribution in the dianion.     

Metallkomplexe von Farbstoffen. VIII Übergangsmetallkomplexe des Curcumins und seiner Derivate

Metal Complexes of Dyes. IX. Transition Metal Complexes of Curcumin and Derivatives The bidentate monoanions of curcumin[CU, (1, 7-bis(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione)], diacetylcurcumin[DACU, (1,7-bis(4-acetyl-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione)], dihydroxycurcumin[DHCU, (1,7-bis(4-hydroxiphenyl)-hepta-1,6-diene-3,5-dione)], dimethylcurcumin [DMCU, (1,7-bis(3,4-dimethoxyphenyl)-hepta-1, 6-diene-3,5-dione)] and trimethylcurcumin[TMCU, (1,7-bis(3,4-dimethoxyphenyl)-4-methylhepta-1,6-diene-3,5-dione)] form with chloro bridged complexes [(R₃P)MCl₂]₂ (M?Pd, Pt; R?phenyl, n-butyl, ethyl, tolyl), [η⁵-C₅Me₅)MCl₂]₂ (M?Rh, Ir), [(η⁶-p-cymene)RuCl₂]₂, [(η³-C₃H₅)PdCl]₂, di-μ-chlorobis[N-(diphenylmethylene)-glycinethylester-(C,N)]-dipalladium(II) and with [(η⁵-C₅Me₅)Co(CO)I₂] monochelate dye complexes. The structure of [(η⁶-p-cymene)(Cl)Ru(DMCU)] was determined by X-ray diffraction. The dichelates (DMCU)₂M with M?Cu, Ni, (CU)₂Pd and the trichelate (CU)₃Fe were obtained. Cationic bipyridine copper(II) complexes with CU, DHCU, and DMCU were sythesized by treating the dye ligands with copper(II) acetate, 2,2′-bipyridine and ammoniumtetrafluoroborate. In comparison to the free 1.3-diketones the dye complexes show a bathochromic shift in the UV/VIS spectra.     

Metallcarbonyl-Synthesen. 23. Kristallstruktur und Reaktionsverhalten von Carbonylmetall-Komplexen des Heptamethylindens

Syntheses of Metal Carbonyls. 23. Crystal Structure and Reactivity of Heptamethylindenyl Carbonyl Metal Complexes Reaction of heptamethylindene (C₉(CH₃)₇, 1 ) with Re₂(CO)₁₀ yields [η⁵-C₉(CH₃)₇]Re(CO)₃ ( 2 ), which reacts with NO⁺BF₄^? to form the cationic complex [{η⁵-C₉(CH₃)₇}Re(CO)₂NO]⁺BF₄^? ( 3 ). Irradiation of 2 with UV light in the presence of triethyl phosphite leads to formation of [η⁵-C₉(CH₃)₇]Re(CO)₂[P(OC₂H₅)₃] ( 4 ). Alkylation of (CH₃)₃SnCl with Ind*Li gives [η¹-C₉(CH₃)₇]Sn(CH₃)₃ ( 5 ). All compounds were characterized by spectroscopic methods. The molecular structures of 3 and 5 were determined by single crystal X-ray diffraction ( 3 : P2₁/n (14), a = 1497.7(4) pm, b = 879.0(2) pm, c = 1609.0(4) pm and β = 110.99(2)°, R₁ = 0.038, wR₂ = 0.080; 5 : P2₁/n (14), a = 726.1(1) pm, b = 2930.7(3) pm, c = 930.0(1) pm and β = 112.834(5)°, R₁ = 0.044, R_w = 0.048). Complexes 2 ? 4 exhibit a piano stool configuration with a η⁵-coordinated permethylindenyl ligand (Ind*). Compound 5 displays a η¹ -coordination of the Ind* ligand. Temperature enhancement causes a hapticity change, as observed by NMR spectroscopy.     

Komplexchemie P-reicher Phosphane und Silylphosphane. III. Die Komplexverbindungen (t-Bu)3P9 · Cr(CO)5 und (t-Bu)3P9 · 2 Cr(CO)5 des Nonaphosphans(3), (t-Bu)3P9

Transition Metal Complexes of P-rich Phosphanes and Silyphosphanes. III. Complex Compounds (t-Bu)₃P₉ · Cr(CO)₅ and (t-Bu)₃P₉ · 2 Cr(CO)₅ Derived from Nonaphosphane (3) (t-Bu)₃P₉ The reaction of (t-Bu)₃P₉ 1 with Cr(CO)₅ · THF in a molar ratio of 1:1 yields (t-Bu)₃P₉ · Cr(CO)₅ 2 (yellow crystals) with the Cr(CO)₅ group coordinated to an equatorial P atom of the P₉ skeleton. In the reaction of 1 with 2 moles of Cr(CO)₅ · THF the complex product (t-Bu)₃P₉ · 2 Cr(CO)₅ 3 is formed with the second Cr(CO)₅ group linked to a basal P atom. Evidence for this comes from ³¹P NMR spectra as well as from crystal structure determinations of 2 and 3.2 crystallizes in the space group P2₁/n with a = 1012,9(2) pm, b = 2961,9(4) pm, c = 983,2(2) pm, β = 101,41(2)° and Z = 4 formula units. 3 crystallizes on the space group Pbcn with a = 2675,8(8) pm, b = 1222,4(2)pm, c = 2212,3 pm and Z = 8. In 2 and 3 the equatorial P atoms opposite to the P₂ dumbbell are complexed. The further complexation in 3 takes place at a basal P atom in Z-arrangement. The distances d(P Cr) are 243.5(1) pm and 240.5(1) pm and 240.5(1) pm for the equatorial P atoms in bf 2 and 3, respectively. For the basal P atom is 3 the distance in 235.7 pm. The P P distance range from 217.5 to 223.0 pm with the shorter ones at the bridgehead atom and the longer one at the P₂ dumbbell. The structures are discussed with that of the free ligand.     

Neue ein- und mehrkernige Komplexe der Lanthanoiden. Zur Reaktion von Ph2Se2 mit Ytterbium

New Mono- and Polynuclear Complexes of the Lanthanides. On the Reaction of Ph₂Se₂ with Ytterbium Surprising formation of different complexes during the reaction of Ytterbium with Dichalcogenides. With THF is the mononuclear complex [Yb(SePh)₃(thf)₃] 1 (space group P31c (No. 159), Z = 2, a = 15.353(3) Å, c = 7.8920(10) Å) built up. In this compound is the Lanthanidion octahedrally souronded by the ligands. Reaction in Toluol/THF leads in contrast to the tetranuclear complex [Yb₄(SePh)₈O₂(thf)₆] 2 (space group C2/c (No. 14), Z = 4, a = 27.084(9) Å, b = 13.021(4) Å, c = 24.002(8) Å, β = 106.13(3)°). In DME it is possible to isolate the ionic species [Yb₃(SePh)₆(dme)₄][Yb(SePh)₄(dme)] 3 (space group P1 (No. 2), Z = 2, a = 11.109(3) Å, b = 11.664(2) Å, c = 36.303(10) Å, α = 84.60(4)°, β = 89.52(3)°, γ = 73.69(2)°). In this reactions are neutral and also ionic complexes accesible.     

Zur Thermodynamik der Dimerisierung von gasförmigem CrI2, MnI2, FeI2 und CoI2: experimentelle und quantenchemische Untersuchungen

Thermodynamic Data of the Dimerisation of Gaseous CrI₂(g), MnI₂(g), FeI₂(g), and CoI₂(g), Experimental and Quantum Chemical Investigations By means of quantum chemical methods molar heats and entropies as a function of temperature for the monomeric and dimeric diiodides of 3d‐metals have been calculated. From mass‐spectrometric measurements of the dimerisation equilibria of gaseous CrI₂, MnI₂, FeI₂, and CoI₂ using the Knudsen‐effusion method the heats of dimerisation and the heats of formation of the monomeric and dimeric iodides could be derived using the results of the quantum chemical calculations.     

Zur Kinetik der Bildung von Arylaminomethylenverbindungen aus Triethoxymethan,Arylaminen und CH2-aciden Verbindungen in einer Dreikomponentenkondensation

Condensation of triethoxymethane and aniline with dimedone gives 2-anilinomethylene dimedone as the main product. An¹H-NMR-spectroscopic investigation of the kinetics in chloroform-d ₁ and methanol-d ₄ shows different rate determining steps in these solvents. There are two predominant rate determining steps in a complicated multistep reaction sequence.The initial one involves condensation of aniline with triethoxymethane to form diphenyl formamidine via ethyl phenyl formimidate. The second step involves reaction of the intermediate diphenyl formamidine with dimedone. The rates are strongly dependent upon the nature of the solvent and the concentration of catalytic acid. In methanol the reaction of dimedone with the intermediate diphenyl formamidine is rate determining. For preparative purposes the isolation of the intermediate diphenyl formamidine and the subsequent use of less polar solvents offer an advantage, because the second step is found to be accelerated.

6. Mitt.:Wolfbeis, O. S., Mh. Chem.112, 369 (1981).     

Zur Reaktion der Lanthanoiden mit Chelatliganden Darstellung und Struktur von [(py2CH)3Gd]

On the Reaction of the Lanthanides with Chelate Ligands Synthesis and Crystal Structure of [(py₂CH)₃Gd] GdBr₃ reacts with [(py₂CH)Li] to the mononuclear complex [(py₂CH)₃Gd] 1 . The structure of 1 was characterized by X-ray single crystal structure analysis. Space group P2₁, Z = 2, a = 951.4(10) pm, b = 1369.4(10) pm, c = 1074.5(10) pm, β = 105.69(8)°. The Gd-Ion is surrounded by the six nitrogen atoms of the three chelate ligands and shows a distorted trigonal prismatic coordination. As a difference to the lithium salt of the ligand, the six-membered metalla-cycles in 1 are not planar, but show a boat conformation.     

Zur Verbindungsbildung von MeO: M2O3. VIII. Synthese und Aufbau der metastabilen Verbindung CaEr3O5,5

Compound Formation of MeO: M₂O₃. VIII. Preparation and Structure of the Metastable Compound CaEr₃O_5,5 Single crystal of CaEr₃O_5,5 were prepared at high temperatures by CO₂-Laser-technique. X-ray structure determination leads to a monoclinic symmetry (Space group C—C2/m; a = 6.524, b = 3.546, c = 11.754 Å, β = 92.32°). There are significant differences between CaEr₃O_5.5 and CaTm₃O_5.5.