Isolation and Characterization of Lewis Base Stabilized Monomeric Parent Stibanylboranes

The synthesis of the Lewis base stabilized monomeric parent compound of stibanylboranes, “H₂Sb? BH₂”, is reported. Through a salt metathesis route, the silyl‐substituted compounds (Me₃Si)₂Sb? BH₂?LB (LB=NMe₃, NHC^Me) were synthesized as representatives of derivatives with a Sb? B σ bond. Under very mild conditions, they could be transformed into the target compounds Me₃N?H₂B? HSb? BH₂?NMe₃ and H₂Sb? BH₂?NHC^Me, respectively. The products were characterized by X‐ray structure analysis, NMR spectroscopy, IR spectroscopy, and mass spectrometry. DFT calculations give further insight into the stability and bonding of these unique compounds.     

Anionic Chains of Parent Pnictogenylboranes

We report on the synthesis and structural characterization of unprecedented anionic parent compounds of mixed Group 13/15 elements. The reactions of the pnictogenylboranes H₂E‐BH₂?NMe₃ ( 1 a =P, 1 b =As) with phosphorus and arsenic centered nucleophiles of the type [EH₂]^? (E=P, As) lead to the formation of compounds of the type [H₂E‐BH₂‐E′H₂]^? ( 2 : E=E′=P; 3 : E=E′=As; 4 : E=P, E′=As) containing anionic pnictogen–boron chain‐like units. Furthermore, a longer 5‐membered chain species [H₂As‐BH₂‐PH₂‐BH₂‐AsH₂]^? ( 5 ) and a cyclic compound [NHC^dipp‐H₂B‐PH₂‐BH₂‐NHC^dipp]⁺[P₅B₅H₁₉]^? ( 6 ) containing a n‐butylcyclohexane‐like anion were obtained. All the compounds have been characterized by X‐ray structure analysis, multinuclear NMR spectroscopy, IR spectroscopy, and mass spectrometry. DFT calculations elucidate their high thermodynamic stability, the charge distribution, and give insight into the reaction pathway.     

Cationic Chains of Phosphanyl‐ and Arsanylboranes

Whilst catena‐phosphorus cations have been intensively studied in the last years, mixed Group 13/15 element cationic chains have not yet been reported. Reaction of the pnictogenboranes H₂EBH₂?NMe₃ (E=P, As) with monohalideboranes lead to the cationic chain compounds [Me₃N?BH₂EH₂BH₂?NMe₃][X] (E=P, As; X=AlCl₄, I) and [Me₃N?BH₂PH₂BH₂PH₂BH₂?NMe₃][X] (X=I, VCl₄(thf)₂), respectively. All of the compounds have been characterized by X‐ray structure analysis, NMR spectroscopy, IR spectroscopy, and mass spectrometry. DFT calculations elucidate the reaction pathway, the high thermodynamic stability, the charge distribution within the chain and confirm the observed solid‐state structures.     

Die Insertion von Sauerstoffatomen in Ga–Ga- und In–In-Bindungen – Bildung von monomeren Verbindungen R2E–O–ER2 [R = CH(SiMe3)2] mit stark aufgeweiteten E–O–E-Winkeln

The Insertion of Oxygen Atoms into Ga–Ga and In–In Bonds – Formation of the Monomeric Compounds R₂E–O–ER₂ [R = CH(SiMe₃)₂] with Strongly Enlarged Angles E–O–E The tetraalkyldielement compounds R₂Ga–GaR₂ ( 1 ) und R₂In–InR₂ ( 2 ) [R = CH(SiMe₃)₂] reacted with trimethylamine N-oxide by the insertion of oxygen atoms in their element-element single bonds. The products R₂E–O–ER₂ are monomeric in the solid state due to the high steric shielding by the voluminous bis(trimethylsilyl)methyl groups. As shown by crystal structure determinations, the E–O–E bridges have large angles of 142.7 (E = Ga, 3 ) and 138.6° (E = In, 4 ) and short separations between the oxygen and the coordinatively unsaturated Ga and In atoms. Both products are extremely hygroscopic.     

Umsetzungen der Dielementverbindungen R2E–ER2 [E = Ga,In; R = CH(SiMe3)2] mit Lithium‐phenylethinid – Bildung von Addukten unter Erhalt der E–E‐Bindungen

Reactions of the Dielement Compounds R₂E–ER₂ [E = Ga, In; R = CH(SiMe₃)₂] with Lithium Phenylethynide – Formation of Adducts by Retention of the E–E Bonds Lithium phenylethynide reacted with the dielement compounds tetrakis[bis(trimethylsilyl)methyl]digallane(4) ( 2 ) and diindane(4) ( 3 ) as a Lewis‐base and gave by the addition of one ethynido ligand to one of the Lewis‐acidic central atoms the anionic adducts 4 and 5 with intact Ga–Ga and In–In single bonds. Thus, compounds were formed, in which tricoordinated, coordinatively unsaturated Ga or In atoms are neighbored to tetracoordinated, coordinatively saturated ones. The E–E bonds [255.83 pm in 4 (Ga–Ga) and 285.24 pm in 5 (In–In)] are only slightly lengthened compared to those of the starting compounds 2 and 3 . A dynamic behavior with a fast change of the position of the ethynido ligand was observed for both compounds in solution at room temperature.     

Bidentate Phosphanyl- and Arsanylboranes

A new class of neutral bidentate ligands with pnictogenyl-functional sites has been obtained. The reaction of tmeda⋅(BH₂I)₂ ( 1 , tmeda=tetramethylethylendiamine) with different phosphanides yields the corresponding bidentate phosphanylboranes tmeda⋅(BH₂PH₂)₂ ( 2 a ), tmeda⋅(BH₂PPh₂)₂ ( 2 b ), and tmeda⋅(BH₂tBuPH)₂ ( 2 c ). This reaction strategy could be further extended to synthesize the first bidentate arsanylborane tmeda⋅(BH₂AsPh₂)₂ ( 3 ). Depending on the substituents on the phosphorus, these compounds form different Au^I complexes, to build either polymeric tmeda⋅(BH₂PH₂AuCl)₂ ( 4 a ), or monomeric tmeda⋅(BH₂PPh₂AuCl)₂ ( 4 b ) products. These compounds form also neutral oligomeric group 13/15 chain-like molecules by coordination to a boron moiety such as tmeda⋅(BH₂PH₂BH₃)₂ ( 5 a ) and tmeda⋅(BH₂AsPh₂BH₃)₂ ( 5 b ). DFT calculations provide insight into the differences between the syntheses of mono- and bidentate pnictogenylboranes.     

An NHC-Stabilized H2GeBH2 Precursor for the Preparation of Cationic Group 13/14/15 Hydride Chains

The synthesis, characterization and reactivity studies of the NHC-stabilized complex IDipp ⋅ GeH₂BH₂OTf ( 1 ) (IDipp=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) are reported. Nucleophilic substitution of the triflate (OTf) group in 1 by phosphine or arsine donors provides access to the cationic group 13/14/15 chains [IDipp ⋅ GeH₂BH₂ERR¹R²]⁺ ( 2 E=P; R, R¹=H; R²=^tBu; 3 E=P; R=H; R¹, R²=Ph; 4 a E=P; R, R¹, R²=Ph; 4 b E=As; R, R¹, R²=Ph). These novel cationic chains were characterized by X-ray crystallography, NMR spectroscopy and mass spectrometry. Moreover, the formation of the parent complexes [IDipp ⋅ GeH₂BH₂PH₃][OTf] ( 5 ) and [IDipp ⋅ GeH₃][OTf] ( 6 ) were achieved by reaction of 1 with PH₃. Accompanying DFT computations give insight into the stability of the formed chains with respect to their decomposition.     

New Reactivity Patterns in 3H-Phosphaallene Chemistry [Aryl-P=C=C(H)-tBu]: Hydroboration of the C=C Bond,Deprotonation and Trimerisation

3H-Phosphaallenes, R−P=C=C(H)C−R’ ( 3 ), are accessible in a multigram scale on a new and facile route and show a fascinating chemical reactivity. BH₃(SMe₂) and 3 a (R=Mes*, R’=tBu) afforded by hydroboration of the C=C bonds of two phosphaallene molecules an unprecedented borane ( 7 ) with the B atom bound to two P=C double bonds. This compound represents a new FLP based on a B and two P atoms. The increased Lewis acidity of the B atom led to a different reaction course upon treatment of 3 a with H₂B-C₆F₅(SMe₂). Hydroboration of a C=C bond of a first phosphaallene is followed in a typical FLP reaction by the coordination of a second phosphaallene molecule via B−C and P−B bond formation to yield a BP₂C₂ heterocycle ( 8 ). Its B−P bond is short and the B-bound P atom has a planar surrounding. Treatment of 3 a with tBuLi resulted in deprotonation of the β-C atom of the phosphaallene ( 9 ). The Li atom is bound to the P atom as demonstrated by crystal structure determination, quantum chemical calculations and reactions with HCl, Cl-SiMe₃ or Cl-PtBu₂. The thermally unstable phosphaallene Ph−P=C=C(H)-tBu gave a unique trimeric secondary product by P−P, P−C and C−C bond formation. It contains a P₂C₄ heterocycle and was isolated as a W(CO)₄ complex with two P atoms coordinated to W ( 15 ).     

Perfluormthyl-Element-Liganden. XVII. Adduktbildung von MenE(CF3)3−n-Liganden mit BX3-Verbindungen (Me = CH3; E = P,As, Sb; n = 0–3; X = H,CH3, Hal)

Perfluoromethyl-Element-Ligands. XVII. Formation of Adducts of Me_nE(CF₃)_3?n Ligands with BX₃ Compounds (Me = CH₃; E = P, As, Sb; n = 0–3; X = H, CH₃, Hal) The ligands Me_nE(CF₃)_3?n (Me = CH₃; E = P, As, Sb; n = 0–3) have been prepared (partly using new methods) and studied by n.m.r. spectroscopy (¹H, ¹⁹F, ³¹P, ¹³C). In order to deduce their relative donor strength their reactions with the Lewis acids “BH₃”, BMe₃, BMe₃, Me₂BBr, and BX₃ (X = F, Cl, Br) have been studied. Control of adduct formation occurs by n.m.r. spectroscopy (¹H, ¹⁹F). The following series of decreasing basicity or acidity are obtained:      

Komplexe von FeI2 und FeI3 mit Tetramethylharnstoff

Complexes of FeI₂ and FeI₃ with Tetramethylurea [FeI₂(OC(NMe₂)₂)₂] ( 1 , [Fe₂I₄(OC(NMe₂)₂)₂] ( 2 ), and [FeI₃(OC(NMe₂)₂] ( 3 ) were prepared by the reaction of FeI₂ and FeI₂/iodine, respectively, with tetramethylurea. The structures of 1 and 3 were determined from single crystal X-ray diffraction data. 1 crystallizes in the triclinic space group P1 , with a = 809.9(1), b = 923.2(1), c = 1 374.6(1) pm, α = 106.80(1), β = 90.47(1), γ = 101.55(1)°; Z = 2; R = 0.045., 3 : monoclinic, P2₁/c, a = 1 311.4(1), b = 783.3(1), c = 1 409.1(1) pm, β = 97.36(1)°; Z = 4; R = 0.047. 1 and 3 are isolated neutral complexes with distorted tetrahedral coordination of iron. 3 is the first FeI₃-complex with an O-donor ligand. The IR-spectra exhibit strong shifts of n?C = O and n?_asC—N of tetramethylurea especially on coordinating to FeI₃.     

Reaktionen von Lithiumhydridosilylamiden RR′(H)Si–N(Li)R″ mit Chlortrimethylsilan in Tetrahydrofuran und unpolaren Lösungsmitteln: N‐Silylierung und/oder Cyclodisilazanbildung

Reactions of Lithium Hydridosilylamides RR′(H)Si–N(Li)R″ with Chlorotrimethylsilane in Tetrahydrofuran and Nonpolar Solvents: N‐Silylation and/or Formation of Cyclodisilazanes The lithiumhydridosilylamides RR′(H)Si–N(Li)R″ ( 2 a : R = R′ = CHMe₂, R″ = SiMe₃; 2 b : R = R′ = Ph, R″ = SiMe₃; 2 c : R = R′ = CMe₃, R″ = SiMe₃; 2 d : R = R′ = R″ = CMe₃; 2 e : R = Me, R′ = Si(SiMe₃)₃, R″ = CMe₃; 2 f – 2 h : R = R′ = Me, f : R″ = 2,4,6‐Me₃C₆H₂, g : R″ = SiH(CHMe₂)₂, h : R″ = SiH(CMe₃)₂; 2 i : R = R′ = CMe₃, R″ = SiH(CMe₃)₂) were prepared by reaction of the corresponding hydridosilylamines RR′(H)Si–NHR″ 2 a – 2 i with n‐butyllithium in equimolar ratio in n‐hexane. The unknown amines 1 e – 1 i and amides 2 f – 2 i have been characterized spectroscopically. The wave numbers of the Si–H stretching vibrations and ²⁹Si–¹H coupling constants of the amides are less than of the analogous amines. This indicates a higher hydride character for the hydrogen atom of the Si–H group in the amide in comparison to the amines. The ²⁹Si‐NMR chemical shifts lie in the amides at higher field than in the amines. The amides 2 a – 2 c and 2 e – 2 g react with chlorotrimethylsilane in THF to give the corresponding N‐silylation products RR′(H)Si–N(SiMe₃)R″ ( 3 a – 3 c , 3 e – 3 g ) in good yields. In the reaction of 2 i with chlorotrimethylsilane in molar ratio 1 : 2,33 in THF hydrogen‐chlorine exchange takes place and after hydrolytic work up of the reaction mixture [(Me₃C)₂(Cl)Si]₂NH ( 5 a ) is obtained. The reaction of the amides 2 a – 2 c , 2 f and 2 g with chlorotrimethylsilane in m(p)‐xylene and/or n‐hexane affords mixtures of N‐substitution products RR′(H)Si–N(SiMe₃)R″ ( 3 a – 3 c , 3 f , 3 g ) and cyclodisilazanes [RR′Si–NR″]₂ ( 6 a – 6 c , 6 f , 6 g ) as the main products. In case of the reaction of 2 h the cyclodisilazane 6 h was obtained only. 2 c – 2 e show a very low reactivity toward chlorotrimetyhlsilane in m‐xylene and toluene resp.. In contrast to Me₃SiCl the reactivity of 2 d toward Me₃SiOSO₂CF₃ and Me₂(H)SiCl is significant higher. 2 d react with Me₃SiOSO₂CF₃ and Me₂(H)SiCl in n‐hexane under N‐silylation to give RR′(H)Si–N(SiMe₃)R″ ( 3 d ) and RR′(H)Si–N(SiHMe₂)R″ ( 3 d ′) resp. The crystal structures of [Me₂Si–NSiMe₃]₂ ( I ) ( 6 f , 6 g and 6 h ) have been determined.     

Einfluß der Ringatome auf die Struktur von Triel‐Pentel‐Heterozyklen – Synthese und Molekülstrukturen von [Me2InAs(SiMe3)2]2 und [Me2InSb(SiMe3)2]3

Influence of the Ring Atoms on the Structure of Triel‐Pentel Heterocycles – Synthesis and X‐Ray Crystal Structures of [Me₂InAs(SiMe₃)₂]₂ and [Me₂InSb(SiMe₃)₂]₃ Triel‐pentel heterocycles [Me₂InE(SiMe₃)₂]_x have been prepared by dehalosilylation reactions from Me₂InCl and E(SiMe₃)₃ (E = As, x = 2; E = Sb, x = 3) and characterised by NMR spectroscopy and by X‐ray crystal structure analyses. In addition the X‐ray crystal structures of [Me₂GaAs(SiMe₃)₂]₂ and [Me₂InP(SiMe₃)₂]₂ are reported. The compounds complete a family of 13 identically substituted heterocycles [Me₂ME(SiMe₃)₂]_x (M = Al, Ga, In; E = N, P, As, Sb, Bi; x = 2, 3), whose structures were investigated depending on the ring atoms M and E. The tendencies that have been observed concerning the ring sizes can be explained by the interplay of the atomic radii of the central atoms and the sterical demand of the ligands. After a formal separation of the M–E bonds in σ bonds and dative bonds the characteristic differences and trends in the endocyclic and exocyclic bond angles of both centres M and E can be interpreted on the basis of a simple Lewis acid/base adduct model.     

Phosphanylalanes and Phosphanylgallanes Stabilized only by a Lewis Base

The synthesis and characterization of the first parent phosphanylalane and phosphanylgallane stabilized only by a Lewis base (LB) are reported. The corresponding substituted compounds, such as IDipp?GaH₂PCy₂ ( 1 ) (IDipp=1,3‐bis(2,6‐diisopropylphenyl)‐imidazolin‐2‐ylidene) were obtained by the reaction of LiPCy₂ with IDipp?GaH₂Cl. However, the LB‐stabilized parent compounds IDipp?GaH₂PH₂ ( 3 ) and IDipp?AlH₂PH₂ ( 4 ) were prepared via a salt metathesis of LiPH₂?DME with IDipp?E′H₂Cl (E′=Ga, Al) or by H₂‐elimination reactions of IDipp?E′H₃ (E′=Ga, Al) and PH₃, respectively. The compounds could be isolated as crystalline solids and completely characterized. Supporting DFT computations gave insight into the reaction pathways as well as into the stability of these compounds with respect to their decomposition behavior.     

Synthesis and Crystal Structures of Novel Copper(I) Complexes of a Phosphanylborane

The novel copper iodide clusters [Cu₃(μ‐I)(μ₃‐I)₂(PH₂BH₂·NMe₃)₃] ( 2 ) and [Cu₄(μ‐I)₂(μ₃‐I)₂(PH₂BH₂·NMe₃)₃] ( 3 ) were synthesized by treating CuI with the primary phosphine (H₂PBH₂·NMe₃). The novel features of both compounds, which have been characterized by X‐ray crystallography, are the unsymmetrical constitution of the copper iodide core due to the influence of the monodentate phosphorus ligand. This results in copper atoms with different coordination numbers within the compound. Complex 2 , the major product of the reaction, contains a distorted octahedral Cu₃I₃‐core, in which one vertex is missing. Complex 3 was isolated as a by‐product and is composed of a Cu₄I₄‐core in a distorted octahedral coordination.     

Monomeric β-Diketiminato Group 13 Metal Dipnictogenide Complexes with Two Terminal EH2 Groups (E=P,As)

The pnictogenyl Group 13 compounds (Dipp₂Nacnac)M[E(SiMe₃)₂]Cl and (Dipp₂Nacnac)M(EH₂)₂ (Dipp₂Nacnac=HC[C(Me)N(Ar)]₂, Ar: Dipp=2,6-iPr₂C₆H₃; M=Al, Ga, In; E=P, As) were successfully synthesized. The salt metathesis between (Dipp₂Nacnac)MCl₂ and LiE(SiMe₃)₂ only led to monosubstituted compounds (Dipp₂Nacnac)M[E(SiMe₃)₂]Cl [E=P, M=Ga( 1 ), In ( 2 ); E=As, M=Ga ( 3 ), In ( 4 )], regardless of the stoichiometric ratios used. In contrast to the steric effect of the SiMe₃ groups in 1 – 4 , the reactions of the corresponding halides with LiPH₂⋅DME (or KAsH₂) facilely yielded the dipnictogenide compounds (Dipp₂Nacnac)M(EH₂)₂ (E=P, M=Al ( 5 ), Ga ( 6 ), In ( 7 ); E=As, M=Al ( 8 ), Ga ( 9 )), avoiding the use of flammable and toxic PH₃ and AsH₃ for their synthesis. The compounds 5 – 9 are the first examples of monomeric Group 13 diphosphanides and diarsanides in which the metal center is bound to two terminal PH₂ and AsH₂ groups, respectively. In contrast to the successful synthesis of the indium diphosphanide (Dipp₂Nacnac)In(PH₂)₂, the reaction of (Dipp₂Nacnac)InCl₂ with KAsH₂ led to an indium mirror due to the instability of the target product.     

The Analysis of Electronic Structures,NBO, EDA,and QTAIM of trans‐(H3P)2(η2‐BH4 )W(≡C‐para‐C6H4X)(CO) Complexes

In the present research, the impact of substitution on the dipole moment, electronic structure, and frontier orbital energy in trans ‐(H₃P )₂(η²‐BH₄ )W(≡C‐para ‐C₆H₄X )(CO ) complexes (X = H, F, SiH₃ , CN , NO₂ , SiMe₃ , CMe₃ , NH₂ , NMe₂ ) was studied with mpw1pw91 quantum chemical computations. The nature of the chemical bond between the trans‐[Cl(η²‐BH₄ )(H₃P ) ₂W ]⁻ and [C‐para ‐C₆H₄X ]⁺ fragments was demonstrated through energy decomposition analysis (EDA ). The percentage composition in terms of the specified groups of frontier orbitals was examined for these complexes to investigate the feature in metal–ligand bonds. Quantum theory of atoms in molecules (QTAIM ) and natural bond orbital (NBO ) analysis were applied to elucidate these complexes’ metal–ligand bonds.     

Synthese und Struktur von η1‐Phosphaallyl‐, η1‐Arsaallylund η1‐Stibaallyleisen‐Komplexen [(η5‐C5Me5)(CO)2Fe–E(SiMe3)C(OSiMe3)=CPh2] (E = P,As, Sb)

Syntheses and Structures of η¹‐Phosphaallyl, η¹‐Arsaallyl, and η¹‐Stibaallyl Iron Complexes [(η⁵‐C₅Me₅)(CO)₂Fe–E(SiMe₃)C(OSiMe₃)=CPh₂] (E = P, As, Sb) The reaction of equimolar amounts of [(η⁵‐C₅Me₅)(CO)₂Fe–E(SiMe₃)₂] ( 1 a : E = P; 1 b : As; 1 c : Sb) and diphenylketene afforded the η¹‐phosphaallyl‐, η¹‐arsaallyl‐, and η¹‐stibaallyl complexes [(η⁵‐C₅Me₅)(CO)₂Fe–E(SiMe₃)C(OSiMe₃)=CPh₂] ( 2 a : E = P; 2 b : As; 2 c : Sb). The molecular structures of 2 b and 2 c were elucidated by single crystal X‐ray analyses.     

Dialkylaminostibane. Präparation und Spektren

Dialkylaminostibanes. Preparation and Spectra The dialkylaminodichlorostibanes Cl₂SbNMe₂ ( 1 ), Cl₂SbNMeEt ( 2 ), and Cl₂SbNEt₂ ( 3 ) as well as the bis(dialkylamino) chlorostibanes ClSb[NMe₂]₂ ( 4 ), ClSb[NMeEt]₂ ( 5 ), and ClSb[NEt₂]₂ ( 6 ) were prepared by exchange reactions between SbCl₃ and Sb[NRR′]₃ (R = R′ = Me ( 7 ); R = R′ = Et ( 8 ); R = Me, R′ = Et ( 9 ). By reaction of 1 and 2 with MeOH and EtOH the dialkylaminoalkoxochlorostibanes ClSbOMe[NMe₂] ( 10 ), ClSbOEt[NMe₂] ( 11 ), and ClSbOEt[NMeEt] ( 12 ) can be prepared. The vibrational spectra of 1–12 were assigned and discussed. 1–4 and 10–12 were associated in the solid state by SbN-bridges to dimeres. An analog association is sterically hinderd for 5–9 .     

Synthesis and selective silylation of ω-hydroxy functionalized (η-alkenyl)carbene complexes of chromium(0) and tungsten(0) Part 11. The chemistry of metallacyclic alkenylcarbene complexes

Tungsten(0) carbene complexes of the type (OC)₅WC(NMeCH₂CHCHCH₂OH)R 2 (R=Me: 2a; R=Ph: 2b) were generated by aminolysis of (OC)₅WC(OMe)R with cis-NHMeCH₂CHCHCH₂OH. Like their Cr-congeners 1, complexes 2 exist at room temperature as mixtures of Z- and E-isomers with regard to the C-N bond. The metallacyclic complexes (OC)₄WC(η²-NMeCH₂CHCHCH₂OH)R (4) were obtained in good yields upon photo-decarbonylation of 2. Deprotonation/silylation of the complexes (OC)₄MC(η²-NMeCH₂CHCHCH₂OH)Me (M=Cr: 3a; M=W: 4a) with one equivalent of ⁿBuLi/Me₃SiCl gave (OC)₄MC(η²-NMeCH₂CHCHCH₂OSiMe₃)CH₃ (M=Cr: 5; M=W: 6), whereas with two equivalents of ⁿBuLi/Me₃SiCl complexes (OC)₄MC(η²-NMeCH₂CHCHCH₂OSiMe₃)CH₂SiMe₃ (M=Cr: 7; M=W: 8) were formed. Hydrolysis of the latter yielded selectively (OC)₄MC(η²-NMeCH₂CHCHCH₂OH)CH₂SiMe₃ (M=Cr: 9; M=W: 10). The complexes 1-10 were analyzed in solution by one- and two-dimensional NMR spectroscopy (¹H, ¹³C, ²⁹Si, ¹H/¹H COSY, ¹H/¹H NOESY, ¹³C/¹H HETCOR).     

Untersuchungen am Chlordiphenyl‐ und Tribenzylstiban sowie am Tribenzyldibromstiboran – Molekülstrukturen und Isotypie

Element–Element Bonds. X. Studies of Chloro(diphenyl)stibane, Tribenzylstibane and Tribenzyldibromostiborane – Molecular Structures and Isotypism Chlorodiphenylstibane ( 1 d ) {P2₁/c; Z = 4; a = 1191.8(1); b = 853.4(1); c = 1112.0(1) pm; β = 93.60(1)°; –100 ± 2 °C} crystallizes isotypically with a series of homologous (H₅C₆)₂E–X compounds (E = As, X = Cl, Br, I; E = Sb, X = Br, I); the structure type of tribenzylstibane ( 5 d ) {Pbca; Z = 8; a = 832.1(2); b = 2681.3(5) pm; c = 1600.9(3); –100 ± 3 °C} is already known from tribenzylmethanol, ‐silanol and ‐silane. Tribenzyldibromostiborane ( 6 ) {P2₁/n; Z = 4; a = 938.4(2); b = 2292.4(5); c = 1019.7(2) pm; β = 112.71(1)°; –100 ± 3 °C} does not show an analogous relationship to known structure types. Characteristic mean bond lengths and angles are { 1 d , Sb–Cl 240.9(1), Sb–C 214.0 pm, Cl–Sb–C 93.8°, C–Sb–C 98.6(1)°; 5 d , Sb–C 217.5(3) pm, C–Sb–C 94.9(6)°; 6 , Sb–Br 264.6; Sb–C 217.0(8) pm, Br–Sb–Br 179.4(1)°; C–Sb–C 120°; Br–Sb–C 84.8(2)° to 94.7(2)°}. Stiborane 6 exhibits very weak intermolecular Sb‥Br interactions of 417 pm which, however, affect the molecular conformation in a striking way.