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1.
A.A. Pasynskii I.V. Skabitsky Yu.V. Torubaev S.G. Sakharov S.S. Shapovalov 《Journal of organometallic chemistry》2009,694(21):3997
The reaction of [Cp′Cr(CO)2(μ-SBu)]2 (1) (Cp′ = MeC5H4) with (PPh3)2Pt(PhCCPh) gives Cp′Cr(CO)2(μ-SBu)Pt(PPh3)2 (2) which could be regarded as a product of the substitution of acetylene ligand at platinum by a monomeric chromium–thiolate fragment. According to the X-ray diffraction analysis 2 contains single Cr–Pt (2.7538(15)) and Pt–S (2.294(2) Å) bonds while Cr–S bond (2.274(3) Å) is shortened in comparison with ordinary Cr–S bonds (2.4107(4)–2.4311(4) Å) in 1. The bonding between Cr–S fragment and platinum atom is similar to the olefine coordination in their platinum complexes. 相似文献
2.
《Journal of organometallic chemistry》1990,393(3):C47-C48
(COT)2U (COT = η-C8H8) reacts in tetrahydrofuran (THF) with I2 to give the monocyclooctatetraenyl compound (COT)UI2(THF)2 (I) which is transformed into (COT)UI2(HMPA)2 (II) upon addition of 2 equiv. of hexamethylphosphoramide. Treatment of I with Kacac (acac = MeCOCHCOMe), KC5Me5 and LiCH2SiMe3 give (COT)U(acac)2 (III), (COT)(C5Me5)UI (IV) and [(COT)U(CH2SiMe3)3]-[Li(THF)3] (V), respectively. 相似文献
3.
《Journal of organometallic chemistry》1994,469(2):C27-C30
[(COT)Ti(μ-Cl)(THF)]2 (1) reacts with K[HBpz3] or K[HB(3,5-Me2pz)3] to give the new monocyclooctatetraenyl half-sandwich complexes (COT)Ti[HBpz3] (2) and (COT)Ti[HB(3,5-Me2pz)3] (3) respectively, as dark green, air-sensitive solids (COT η8-cyclooctatetraenyl(2-)). The molecular structure of 2 has been determined by an X-ray diffraction study. The monomeric organotitanium(III) complexes (COT)Ti[PhC(NSiMe3) 2](THF) (4), (COT)Ti[MeOC6H4C(NSiMe3)2](THF) (5) and (COT)Ti[Ph2P (NSiMe3)2] (6) have been prepared by treatment of [(COT)Ti(μ-Cl)(THF)]2 (1) with the corresponding heteroallylic ligands. 相似文献
4.
Helmut Fischer Frank Kirchbauer Angelika Früh Mokhles M. Abd-Elzaher Gerhard Roth Christoph C. Karl Markus Dede 《Journal of organometallic chemistry》2001,620(1-2)
Imines, Im, such as MeN=C(Ph)H (5), 2-methyl 4,5-dihydrothiazole (8a), 2-methyl 4,5-dihydrooxazole (8b) and MeN=C(OMe)Me (13) add to the α-carbon atom of the vinylidene ligand in [(CO)5Cr=C=CMe2] (4) to give isolable zwitterionic adducts, [(CO)5Cr−–C(=CMe2)(Im+)]. The reaction of [(CO)5W=C=CPh2] (12) with 13 also yields an adduct, [(CO)5W−–C(=CPh2){NMe=C(OMe)Me}+] (15), whereas from the corresponding reaction of 4 with xanthylideneimine, H–N=C(C6H4)2O (16), a carbene complex, [(CO)5Cr=C(i-Pr)–N=C(C6H4)2O] (17), is obtained. Complex 17 presumably is formed by initial addition of 16 to 4 and subsequently rapid rearrangement. In solution, the adduct [(CO)5Cr−–C(=CMe2)(NMe=C(Ph)H)+] (6) slowly cyclizes to form the 2-azetidin-1-ylidene complex [(CO)5Cr=
Me2] (7). In contrast, when solution of those zwitterions are heated that are formed by addition of 4,5-dihydrothiazole or 4,5-dihydrooxazole to 4, no cyclization is observed but rather the formation of 4,5-dihydrothiazole and 4,5-dihydrooxazole complexes, respectively. The structures of two adducts, [(CO)5Cr−–C(=CMe2)(Im+)] (Im=MeN=C(Ph)H, 2-methyl 4,5-dihydrothiazole) and of the substitution product [(CO)5W(2-methyl 4,5-dihydrothiazole)] have been established by X-ray structural analyses. 相似文献
5.
Manoja K. Samantaray Mobin M. Shaikh Prasenjit Ghosh 《Journal of organometallic chemistry》2009,694(21):3477-3486
Highly convenient copper-free and amine-free Sonogashira coupling of aryl bromides and iodides with terminal acetylenes under amenable conditions in air and in a mixed aqueous medium are reported using several new, user friendly and robust palladium precatalysts (1–5) of N/O-functionalized N-heterocyclic carbenes (NHCs). In particular, the precatalysts, 1 and 2, were synthesized from the imidazolium chloride salts by the treatment with PdCl2 in pyridine in presence of K2CO3 as a base while the precatalysts, 3–5, were synthesized from the respective silver complexes by the treatment with (COD)PdCl2. The DFT studies carried out on the 1–5 complexes suggest the presence of strong NHC–Pd σ-interactions arising out of deeply buried NHC–Pd σ-bonding molecular orbitals (MOs) that account for the inert nature of the metal–carbene bonds and also provide insights into the exceptional stability of these precatalysts. 相似文献
6.
Sally A. Wasileski Michael J. Weaver Marc T. M. Koper 《Journal of Electroanalytical Chemistry》2001,500(1-2)
Density functional theory (DFT) using the finite cluster approach is utilized to compute binding energies, bond geometries, and vibrational properties of carbon monoxide adsorbed on Pt(111) as a function of the external interfacial field, focusing attention on the metal–CO bond itself. Comparison with electrode potential-dependent frequencies for the metal–CO (νM–CO) as well as the much-studied intramolecular C---O (νCO) vibration, as measured by in-situ Raman and infrared spectroscopy, facilitate their interpretation in terms of metal-chemisorbate bonding for this archetypal electrochemical system. Decomposing the calculated metal–CO binding energy and vibrational frequencies into individual orbital and steric repulsion components enables the role of such quantum-chemical interactions to the field- (and hence potential-) dependent bonding to be assessed. No simple relationship between the field(F)-dependent binding energies and the νM–CO frequencies is evident. While the DFT νM–CO–F slopes are negative at positive and small–moderate negative fields, reflecting the prevailing influence of back-donation, a νM–CO–F maximum is obtained at larger negative fields for atop CO, and a plateau for hollow-site CO. This Stark-tuning behavior reflects largely offsetting field-dependent contributions from π and σ surface bonding, and can also be rationalized on the basis of changes in the electrostatic component of νM–CO from increasing M–CO charge polarization. A rough correlation between the field-dependent νM–CO frequencies and the corresponding bond distances, rM–CO, is observed for hollow and atop CO in that rM–CO shortens towards less positive fields, but becomes near-constant at moderate–large negative fields. A more quantitative correlation between the field-dependent C---O frequencies and bond lengths is also evident. In harmony with earlier findings (and unlike the νM–CO–F behavior), the νCO–F dependence is due chiefly to changes in the back-donation bonding component. The overall vibrational frequency-field behavior predicted by DFT is also in semi-quantitative concordance with experimental potential-dependent spectra. 相似文献
7.
Natalia V. Belkova Elena S. Shubina Evgenii I. Gutsul Lina M. Epstein Igor L. Eremenko Sergei E. Nefedov 《Journal of organometallic chemistry》2000,610(1-2)
The interaction of rhenium hydrides ReHX(CO)(NO)(PR3)2 1 (X=H, R=Me (a), Et (b), iPr (c); X=Cl, R=Me (d)) with a series of proton donors (indole, phenols, fluorinated alcohols, trifluoroacetic acid) was studied by variable temperature IR spectroscopy. The conditions governing the hydrogen bonding ReHHX in solution and in the solid state (IR, X-ray) were elucidated. Spectroscopic and thermodynamic characteristics (−ΔH=2.3–6.1 kcal mol−1) of these hydrogen bonded complexes were obtained. IR spectral evidence that hydrogen bonding with hydride atom precedes proton transfer and the dihydrogen complex formation was found. Hydrogen bonded complex of ReH2(CO)(NO)(PMe3)2 with indole (2a–indole) and organyloxy-complex ReH(OC6H4NO2)(CO)(NO)(PMe3)2 (5a) were characterized by single-crystal X-ray diffraction. A short NHHRe (1.79(5) Å) distance was found in the 2a–indole complex, where the indole molecule lies in the plane of the Re(NO)(CO) fragment (with dihedral angle between the planes 0.01°). 相似文献
8.
Dipak Kumar Dutta J. Derek Woollins Alexandra M.Z. Slawin Amy L. Fuller Biswajit Deb Podma Pollov Sarmah Madan Gopal Pathak Dilip Konwar 《Journal of molecular catalysis. A, Chemical》2009,313(1-2):100-106
The reaction of dimeric rhodium precursor [Rh(CO)2Cl]2 with two molar equivalent of 1,1,1-tris(diphenylphosphinomethyl)ethane trichalcogenide ligands, [CH3C(CH2P(X)Ph2)3](L), where X = O(a), S(b) and Se(c) affords the complexes of the type [Rh(CO)2Cl(L)] (1a–1c). The complexes 1a–1c have been characterized by elemental analyses, mass spectrometry, IR and NMR (1H, 31P and 13C) spectroscopy and the ligands a–c are structurally determined by single crystal X-ray diffraction. 1a–1c undergo oxidative addition (OA) reactions with different electrophiles such as CH3I, C2H5I and C6H5CH2Cl to give Rh(III) complexes of the types [Rh(CO)(COR)ClXL] {R = –CH3 (2a–2c), –C2H5 (3a–3c); X = I and R = –CH2C6H5 (4a–4c); X = Cl}. Kinetic data for the reaction of a–c with CH3I indicate a first-order reaction. The catalytic activity of 1a–1c for the carbonylation of methanol to acetic acid and its ester is evaluated and a higher turn over number (TON = 1564–1723) is obtained compared to that of the well-known commercial species [Rh(CO)2I2]− (TON = 1000) under the reaction conditions: temperature 130 ± 2 °C, pressure 30 ± 2 bar and time 1 h. 相似文献
9.
A.Z. El-Sonbati A.A. Al-Sarawy M. Moqbel 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,74(2):463-468
Novel supramolecular rare earth polymeric hydrazone complexes of 5-sulphadiazineazo-3-phenyl-2-thiaxo-4-thiazolidinone (HL) of the composition [(Ln)2(HL)3(NO3)6]n (where Ln = La(1), Y(2), Pr(3), Nd(4), Sm(5), Gd(6) and Ho(7)) have been prepared and characterized on the basis of their chemical analyses, magnetic measurements, conductance, visible and IR spectral data. Composition, conductance and IR spectral data of complexes show that all these act as a tetradentate ligand. Electronic spectra indicate weak covalent character in the metal–ligand bond. The spectra of Nd3+ and Ho3+ show characteristic f–f transitions and the metal–ligand covalency in % has been evaluated. The spectral properties of the above polymeric complexes are also discussed. 相似文献
10.
Gnül Yenilmez ifti Mahmut Durmu Elif enkuytu Adem Kl 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,74(4):881-886
This study dealt with the reactions of hexachlorocyclotriphosphazatriene, N3P3Cl6 (trimer) (1) with phenolphthalein (2) to give the phenolphthalein bridged compounds 3, 4 and 5. The phenolphthalein bridged cyclotriphosphazatriene derivatives are reported for the first time. The new compounds (3–5) are characterized by elemental analysis, mass spectrometry, UV–vis, FT-IR, 1H, 31P NMR and fluorescence spectroscopy. The more bridged phenolphthalein groups show the higher intensity of the absorption bands in the UV–vis spectra. Fluorescence spectrum of compound 3 shows a small band in the lower spectral range, while the spectra of compounds 4 and 5 show more intense and a band in higher spectral range. 相似文献
11.
《Journal of organometallic chemistry》1994,469(1):C15-C18
The cerocene(III) derivatives [Li(THF)4][Ce(COT)2] (1) and (THF)3Na(μ-COT)Ce(COT) (2) have been prepared and characterized structurally by an X-ray diffraction study (COT η8-cycloocta-tetraenyl(2−)). The molecular structures differ significantly, depending on the nature of the alkali metal cation. In the solid state, compound 1 consists of separated ion pairs. In 2 a cyclooctatetraenyl ligand bridges cerium and sodium to give a linear (COT)Ce(μ-COT)Na arrangement. 相似文献
12.
Kentaro Yamane Satoko Hayashi Waro Nakanishi Takahiro Sasamori Norihiro Tokitoh 《Polyhedron》2008,27(18):3557-3566
8-G-1-(p-YC6H4CCSe)C10H6 [2 (G = Cl) and 3 (G = Br): Y = H (a), OMe (b), Me (c), F (d), Cl (e), CN (f) and NO2 (g)] have been prepared and the NMR spectra measured, in addition to 1 (G = H). Structures have been determined by X-ray crystallographic analysis for 2b, 2e and 2g, which are all type B (B), where the Se–Csp bond is placed in the naphthyl plane in B. The type is classified as A if the Se–Csp bond is perpendicular to the naphthyl plane. Structures around the p-YC6H4 (Ar) group are pd (perpendicular) for Y = OMe (2b) and Cl (2e) and pl (planar) for Y = NO2 (2g), where the Se–CNap bond is placed in the aryl plane in pl and perpendicular to the plane in pd. The 1b (A: pd) structure changes dramatically on going to 2b (B: pd) with G = Cl at the 8-position. The effect is called the G-dependence in 2. The G-dependence arises from the energy lowering effect of the np(Cl)σ*(Se–Csp) 3c–4e interaction. Structures are both (B: pd) for 1e and 2e and both (B: pl) for 1g and 2g. One may realize that the structures are unchanged by G = Cl in place of G = H for Y = Cl and NO2 at a first glance. However, the B structures in 2e and 2g must be much more stabilized by the G-dependence of the np(Cl)σ*(Se–Csp) 3c–4e interaction or the GSe–Csp–Csp–Csp2 5c–6e type interaction. The structures of 2 and 3 are examined in solution based on the NMR parameters. The results show that 2 and 3 behave very similarly to each other and the structures are predominantly B, with some equilibrium between pd and pl around the aryl groups in solution. Quantum chemical calculations support the observations. 相似文献
13.
Di Sun Geng-Geng Luo Na Zhang Jian-Hua Chen Rong-Bin Huang Li-Rong Lin Lan-Sun Zheng 《Polyhedron》2009,28(14):2983-2988
Using the principle of crystal engineering, three new silver metal–organic coordination polymers, [Ag2(L1)2(L2)]·2H2O (1), [Ag2(L1)2(L3)]·H2O (2), [Ag2(L1)2(L4)]·2H2O (3) (L1 = 2-aminopyrimidine, L2 = oxalate anion, L3 = glutarate anion and L4 = 1,4-naphthalenedicarboxylate anion) have been synthesized by solution phase reactions of silver nitrate with various dicarboxylic acids and cooperative heterocyclic 2-aminopyrimidine ligand under the ammoniacal conditions. All the complexes have been characterized by elemental analyses, IR spectra and X-ray diffraction. In complex 1, L1 ligands are coordinated to Ag(I) metal centers in rare tridentate fashions, forming one-dimensional (1-D) ladder-like structure, which is interlinked by L2 anions to generate 2-D pleated molecular sheet. Complex 2 displays an interesting two-dimensional (2-D) tongue-and-groove structure containing a new kind of “T-shaped” unit. Meanwhile, each of 2-D bilayers is interlocked by four adjacent identical motifs to form three-dimensional (3-D) 5-fold interpenetrating conformation with weak Ag···Ag interactions. In complex 3, L1 ligands are coordinated to the Ag(I) ions to form 1-D polymeric chain. And L4 anions, acting as bridging linkers through corresponding μ2-carboxylates, link a pair of Ag(I) atoms from adjacent chains to yield 3-D supramolecular network. The structures of complexes 1–3 which span from 2-D to 3-D networks suggest that dicarboxylate anions play important role in the formation of such coordination architectures. 相似文献
14.
Maheswaran Hariharasarma Charles H. Lake Charles L. Watkins Gary M. Gray 《Journal of organometallic chemistry》1999,580(2):1541
Chlorodiphenylphosphine and 2,2′-biphenylylenephosphorochloridite react with 2-hydroxy-2′-(1,4-bisoxo-6-hexanol)-1,1′-biphenyl to yield the new α,ω-bis(phosphorus-donor)-polyether ligands, 2-Ph2PO(CH2CH2O)2–C12H8-2′-OPPh2 (1) and 2-(2,2′-O2C12H8)P(CH2CH2O)2–C12H8-2′-P(2,2′-O2C12H8) (2). These ligands react with Mo(CO)4(nbd) to form the monomeric metallacrown ethers, cis-Mo(CO)4{2-Ph2PO(CH2CH2O)2–C12H8-2′-OPPh2} (cis-3) and cis-Mo(CO)4{2-(2,2′-O2C12H8)P(CH2CH2O)2–C12H8-2′-P(2,2′-O2C12H8)} (cis-4), in good yields. The X-ray crystal structures of cis-3 and cis-4 are significantly different, especially in the conformation of the metal center and the adjacent ethylene group. The very different 13C-NMR coordination chemical shifts of this ethylene group in cis-3 and cis-4 suggest that the solution conformations of these metallacrown ethers are also quite different. Both metallacrown ethers undergo cis–trans isomerization in the presence of HgCl2. Although the cis–trans equilibrium constants for the isomerization reactions are nearly identical, the isomerization of cis-3 is more rapid. Phenyl lithium reacts with cis-3 to form the corresponding benzoyl complexes but does not react with either trans-3 or cis-4. Both the slower rate of cis–trans isomerization of cis-4 and its lack of reaction with PhLi are consistent with weaker interactions between the hard metal cations and the carbonyl oxygens in both trans-3 and cis-4. 相似文献
15.
Reactions of the dichloroboryl complex of osmium, Os(BCl2)Cl(CO)(PPh3)2, with water, alcohols, and amines: Crystal structures of Os[B(OH)2]Cl(CO)(PPh3)2, Os[B(OEt)2]Cl(CO)(PPh3)2, and
George R. Clark Geoffrey J. Irvine Warren R. Roper L. James Wright 《Journal of organometallic chemistry》2003,680(1-2):81
Reaction between the dichloroboryl complex, Os(BCl2)Cl(CO)(PPh3)2, and water replaces both chloride substituents on the boryl ligand, without cleavage of the Os---B bond, giving yellow Os[B(OH)2]Cl(CO)(PPh3)2 (1). Compound 1 can be regarded as an example of a ‘metalla–boronic acid’ (LnM---B(OH)2) and in the solid state, X-ray crystal structure determination reveals that molecules of 1 are tetragonal pyramidal in geometry (Os---B, 2.056(3) Å) and are arranged in pairs, as hydrogen-bonded dimers. This same arrangement is found in the crystalline state for simple boronic acids. Reaction between the dichloroboryl complex, Os(BCl2)Cl(CO)(PPh3)2, and methanol and ethanol produces yellow Os[B(OMe)2]Cl(CO)(PPh3)2 (2a) and yellow Os[B(OEt)2]Cl(CO)(PPh3)2 (2b), respectively. The crystal structure of 2b reveals a tetragonal pyramidal geometry with the diethoxyboryl ligand in the apical site and with an Os---B bond distance of 2.081(5) Å. Reaction between Os(BCl2)Cl(CO)(PPh3)2, and N,N′-dimethyl-o-phenylenediamine and N,N′-dimethyl-ethylenediamine produces yellow
(5) and yellow
(6), respectively. Compounds 1, 2a, 2b, 5, and 6 all react with carbon monoxide to give the colourless, six-coordinate complexes Os[B(OH)2]Cl(CO)2(PPh3)2 (3), Os[B(OMe)2]Cl(CO)2(PPh3)2 (4a), Os[B(OEt)2]Cl(CO)2(PPh3)2 (4b),
(7), and
(8), respectively, but in the case of 6 only, this CO uptake is easily reversible. The crystal structure of 5 is also reported. 相似文献
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16.
FTIR studies of the thermal and photochemical reactions of Os(N(O)H)(CO)Cl2(PPh3)2 (1) are described. Though 1 is relatively stable, it readily reacts when irradiated to form multiple products, including a metal–carbonyl species and N2O, the decomposition product of HNO. The relative yields of products varied depending on whether or not excess CO was present. A model is presented that includes initial photochemical release of HNO from 1 as a significant but not exclusive photoreaction. 相似文献
17.
In order to study the effects of R group on Fe–Hg interactions and 31P chemical shifts, the structures of mononuclear complexes Fe(CO)3(PPh2R)2 (R=pym:1, fur: 2, py: 3,thi: 4; pym=pyrimidine, fur=furyl, py=pyridine, thi=thiazole) and binuclear complexes [Fe(CO)3(PPh2R)2(HgCl2)] (R=pym: 5, fur: 6, py: 7, thi: 8) were studied using the density functional theory (DFT) PBE0 method. The 31P chemical shifts were calculated by PBE0-GIAO method. Nature bond orbital (NBO) analyses were also performed to explain the nature of the Fe–Hg interactions. The conclusions can be drawn as follows: (1) The complexes with nitrogen donor atoms are more stable than those with O or S atoms. The more N atoms there are, the higher is the stabilility of the complex. (2) The Fe–Hg interactions play a dominant role in the stabilities of the complexes. In 5 or 6, thereisa σ-bond between Fe and Hg atoms. However, in 7 and 8, the Fe–Hg interactions act as σP–Fe→nHg and σC–Fe→nHg delocalization. (3) Through Fe→Hg interactions, there is charge transfer from R groups towards the P, Fe, and Hg atoms, which increases the electron density on P nucleus in binuclear complexes. As a result, compared with their mononuclear complexes, the 31P chemical shifts in binuclear complexes show some reduction. 相似文献
18.
The nature of the protonation reaction of (
o(CO)3 (M = Mo, W; R = Me, Ph, p-MeC6H4) (2) (obtained from (CO)3CpMCH2CCR (1) and Co2(CO)8) to give (CO)3
Cp(CO)2 (3) was further investigated by a crossover experiment. Thus, reaction of an equimolar mixture of 2b (M = W, Cp = η5-C5H5, R = Ph) and 2e (M = W, Cp = η5-C5H4Me; R = p-MeC6H4) with CF3COOH affords only 3b (same M, Cp, and R as 2b) and 3e (same M, Cp, and R as 2e) to show an intramolecular nature of this transformation. Reaction of (CO)3CpWCH2CCPh (1b) with Co4(CO)12 was also examined and found to yield 2b exclusively. Treatment of 1 with Cp2Mo2(CO)4 at 0–5°C provides thermally sensitive compounds, possibly (CO)2Cp
oCp(CO)2 (5), which decompose at room temperature to give Cp2Mo2(CO)6 as the only isolated product. 相似文献
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19.
Reaction of NiX2·DME (X = Cl, Br; DME = 1,2-Dimethoxyethane) with Cp′Li (Cp′ = η5-C5Me5) in THF at ?10°C yields as intermediates dimeric halogeno complexes [Cp′NiX]2 (I) as shown by mass spectroscopy. 1 reacts with neutral and anionic donor ligands viz. PPh3 to Cp′Ni(PPh3)X, 1,5-COD to [Cp′NiCOD]+, CpNa to CpCp′Ni and with COTLi2 to (Cp′Ni)2COT (COT = cyclooctatetraene). Analogously the reaction product from FeBr2·DME and Cp′Li at ?80°C in THF is converted by CpNa to CpCp′Fe and by CO to Cp′Fe(CO)2Br. 相似文献
20.
Reinhold Tacke Thomas Kornek Tilman Heinrich Christian Burschka Martin Penka Melanie Pülm Christine Keim Ernst Mutschler Günter Lambrecht 《Journal of organometallic chemistry》2001,640(1-2):140-165
The C/Si/Ge-analogous compounds rac-Ph(c-C5H9)El(CH2OH)CH2CH2NR2 (NR2=piperidino; El=C, rac-3a; El=Si, rac-3b; El=Ge, rac-3c) and (c-C5H9)2El(CH2OH)CH2CH2NR2 (NR2=piperidino; El=C, 5a; El=Si, 5b; El=Ge, 5c) were prepared in multi-step syntheses. The (R)- and (S)-enantiomers of 3a–c were obtained by resolution of the respective racemates using the antipodes of O,O′-dibenzoyltartaric acid (resolution of rac-3a), O,O′-di-p-toluoyltartaric acid (resolution of rac-3b), or 1,1′-binaphthyl-2,2′-diyl hydrogen phosphate (resolution of rac-3c). The enantiomeric purities of (R)-3a–c and (S)-3a–c were ≥98% ee (determined by 1H-NMR spectroscopy using a chiral solvating agent). Reaction of rac-3a–c, (R)-3a–c, (S)-3a–c, and 5a–c with methyl iodide gave the corresponding methylammonium iodides rac-4a–c, (R)-4a–c, (S)-4a–c, and 6a–c (3a–c→4a–c; 5a–c→6a–c). The absolute configuration of (S)-3a was determined by a single-crystal X-ray diffraction analysis of its (R,R)-O,O′-dibenzoyltartrate. The absolute configurations of the silicon analog (R)-4b and germanium analog (R)-4c were also determined by single-crystal X-ray diffraction. The chiroptical properties of the (R)- and (S)-enantiomers of 3a–c, 3a–c·HCl, and 4a–c were studied by ORD measurements. In addition, the C/Si/Ge analogs (R)-3a–c, (S)-3a–c, (R)-4a–c, (S)-4a–c, 5a–c, and 6a–c were studied for their affinities at recombinant human muscarinic M1, M2, M3, M4, and M5 receptors stably expressed in CHO-K1 cells (radioligand binding experiments with [3H]N-methylscopolamine as the radioligand). For reasons of comparison, the known C/Si/Ge analogs Ph2El(CH2OH)CH2CH2NR2 (NR2=piperidino; El=C, 7a; El=Si, 7b; El=Ge, 7c) and the corresponding methylammonium iodides 8a–c were included in these studies. According to these experiments, all the C/Si/Ge analogs behaved as simple competitive antagonists at M1–M5 receptors. The receptor subtype affinities of the individual carbon, silicon, and germanium analogs 3a–8a, 3b–8b, and 3c–8c were similar, indicating a strongly pronounced C/Si/Ge bioisosterism. The (R)-enantiomers (eutomers) of 3a–c and 4a–c exhibited higher affinities (up to 22.4 fold) for M1–M5 receptors than their corresponding (S)-antipodes (distomers), the stereoselectivity ratios being higher at M1, M3, M4, and M5 than at M2 receptors, and higher for the methylammonium compounds (4a–c) than for the amines (3a–c). With a few exceptions, compounds 5a–c, 6a–c, 7a–c, and 8a–c displayed lower affinities for M1–M5 receptors than the related (R)-enantiomers of 3a–c and 4a–c. The stereoselective interaction of the enantiomers of 3a–c and 4a–c with M1–M5 receptors is best explained in terms of opposite binding of the phenyl and cyclopentyl ring of the (R)- and (S)-enantiomers. The highest receptor subtype selectivity was observed for the germanium compound (R)-4c at M1/M2 receptors (12.9-fold). 相似文献