Metal-selenolate chemistry: stereochemistry of adamantane-type clusters of formula [(μ-SePh)6(MSePh)4]2− (M = Zn and Cd)

1992 ◽  
Vol 70 (3) ◽  
pp. 792-801 ◽  
Author(s):  
Jagadese J. Vittal ◽  
Philip A. W. Dean ◽  
Nicholas C. Payne

The structures of three tetramethylammonium salts containing anions of formula [(μ-SePh)6(MSePh)4]2− (M = Zn and Cd) were determined by single crystal X-ray diffraction techniques. The Zn salt crystallizes in different space groups depending upon the solvent combination used in the synthesis. Thus crystals of (Me4N)2[Zn4(SePh)10], 1, grown from a mixture of methanol, acetonitrile, and acetone are triclinic, space group [Formula: see text] with cell dimensions a = 13.214(2), b = 23.859(2), c = 13.072(1) Å, α = 91.134(8), β = 113.350(8), γ = 79.865(9)°, and Z = 2. In the absence of acetone, a solvated crystal (Me4N)2[Zn4(SePh)10]•CH3CN, 2, is formed, which belongs to the monoclinic space group P21/n with a = 14.248(1), b = 39.722(2), c = 13.408(1) Å, β = 97.132(5)°, and Z = 4. The Cd salt (Me4N)2[Cd4(SePh)10], 3, crystallizes in the monoclinic space group P21/c, with a = 20.830(2), b = 14.282(1), c = 25.872(1) Å, β = 99.626(6)°, and Z = 4. These three salts are the first examples of homoleptic, tetranuclear selenolatometal(II) anions with (μ-Se)6M4 cages of adamantane-type stereochemistry. In each case the phenyl substituents of the bridging ligands adopt the configuration [aae, aae, aee, aee], which has the minimum number of two 1,3-axial–axial non-bonding substituent interactions. Keywords: selenolate complexes, synthesis, X-ray crystallography, isomerism, adamantane stereochemistry.

1995 ◽  
Vol 50 (7) ◽  
pp. 1018-1024 ◽  
Author(s):  
Axel Michalides ◽  
Dagmar Henschel ◽  
Armand Blaschette ◽  
Peter G. Jones

In a systematic search for supramolecular complexes involving all combinations of the cyclic polyethers 12-crown-4 (12C4), 15-crown-5 (15C 5), 18-crown-6 (18C 6) and dibenzo- 18-crown-6 (DB -18C6), and the geminal di- or trisulfones H2C(SO 2Me)2, H2C (SO2Et)2 and HC (SO2Me)3-n (SO2Et)n (n = 0 -3 ) , only the following four complexes could be isolated and unequivocally characterized by elemental analysis and 1H NMR spectroscopy: [(12C4){H2C (SO2Et)2}2] (3), [(18C6){H2C (S O2Me)2}] (4), [(DB -18C 6){H2C (SO2Et)2}] (5) and [(D B -18C 6)2{HC (SO2Me )(SO2Et)2}3] (6). The structure of 3 (triclinic, space group P1̄) consists of crystallographically centrosymmetric formula units, in which the disulfone molecules are bonded on each side of the ring by two C -H ··· O(crown) interactions originating from the central methylene group (H···O 213 pm) and from the methylene group of one EtSO2 moiety ( H ··· O 237 pm). Formula units related by translation are connected into parallel strands by a third type of reciprocal C -H ···O bond (H ···O 232 pm) between the second H atom of the central methylene group and a sulfonyl oxygen atom of the adjacent unit. The structure of 4 (monoclinic, space group C2/c) showed severe disorder of the crown ether and could not be refined satisfactorily. Compounds 5 and 6 crystallized as long and extremely thin fibres, indicative of linear-polymeric supramolecular structures; single crystals for X-ray crystallography were not available.


2005 ◽  
Vol 60 (9) ◽  
pp. 978-983 ◽  
Author(s):  
Sevim Hamamci ◽  
Veysel T. Yilmaz ◽  
William T. A. Harrison

Two new saccharinato-silver(I) (sac) complexes, [Ag(sac)(ampy)] (1), and [Ag2(sac)2(μ-aepy)2] (2), [ampy = 2-(aminomethyl)pyridine, aepy = 2-(2-aminoethyl)pyridine], have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group P21/c and triclinic space group P1̄, respectively. The silver(I) ions in both complexes 1 and 2 exhibit a distorted T-shaped AgN3 coordination geometry. 1 consists of individual molecules connected into chains by N-H···O hydrogen bonds. There are two crystallographically distinct dimers in the unit cell of 2 and in each dimer, the aepy ligands act as a bridge between two silver(I) centers, resulting in short argentophilic contacts [Ag1···Ag1 = 3.0199(4) Å and Ag2···Ag2 = 2.9894(4) Å ]. Symmetry equivalent dimers of 2 are connected by N-H···O hydrogen bonds into chains, which are further linked by aromatic π(py)···π(py) stacking interactions into sheets.


1997 ◽  
Vol 50 (10) ◽  
pp. 991 ◽  
Author(s):  
Ian R. Whittall ◽  
Mark G. Humphrey ◽  
David C. R. Hockless

The structures of Au(4-C≡CC6H4XYC6H4-4′-NO2)(PPh3) (XY = (E )-CH=CH (1), (Z)-CH=CH (2), C≡C (3), N=CH (4)) have been determined by single-crystal X-ray diffraction analyses, refining by full-matrix least-squares analysis. For (1), crystals are triclinic, space group P-1, with a8·847(1), b 17·870(4), c 19·705(3) Å, α116·25(1), β 93·33(1), γ 92·64(2)˚, Z 4, 6747 unique reflections (703 parameters), converging at R 0·025 and Rw 0·029. For (2), crystals are monoclinic, space group P 21/a, with a 10·718(6), b 19·398(5), c14·469(3) Å, β 108·96(2)˚, Z 4, 3295 unique reflections (352 parameters), converging atR 0·040 and Rw 0·034. For (3), crystals are triclinic, space group P-1, with a 10·671(4), b 17·599(7), c 18·220(8) Å, α 116·31(3), β 105·00(4), γ 95·08(4)˚, Z 4, 4828 unique reflections (703 parameters), converging at R 0·043 and Rw 0·030. For (4), crystals are triclinic, space group P-1, with a 8·8314(6), b 17·834(2), c 20·001(2) Å, α 115·249(7), β 90·930(7), γ 94·082(7)˚, Z 4, 4724 unique reflections (703 parameters), converging at R 0·035 and Rw 0·034. Despite the [ligated metal donor]-bridge-[nitro acceptor] composition of these complexes, Au–C and C≡C distances are normal and consistent with minimal allenylidene contribution to the ground-state geometry. Within the 3σ confidence limits, the structural data do not provide evidence for π*-back-bonding in these complexes


Author(s):  
Sandeep Kumar ◽  
Ruchi Khajuria ◽  
Amanpreet Kaur Jassal ◽  
Geeta Hundal ◽  
Maninder S. Hundal ◽  
...  

Donor-stabilized addition complexes of nickel(II) with disubstituted diphenyldithiophosphates, [{(ArO)2PS2}2NiL2] {Ar = 2,4-(CH3)2C6H3[(1), (5)], 2,5-(CH3)2C6H3[(2), (6)], 3,4-(CH3)2C6H3[(3), (7)] and 3,5-(CH3)2C6H3[(4), (8)];L= C5H5N [(1)–(4)] and C7H9N [(5)–(8)]}, were successfully isolated and characterized by elemental analysis, magnetic moment, IR spectroscopy and single-crystal X-ray analysis. Compound (4) crystallizes in the monoclinic space groupP21/nwhereas compounds (7) and (8) crystallize in the triclinic space group P\bar 1. The single-crystal X-ray diffraction analysis of (4), (7) and (8) reveals a six-coordinated octahedral geometry for the NiS4N2chromophore. Two diphenyldithiophosphate ions act as bidentate ligands with their S atoms coordinated to the Ni centre. Each of them forms a four-membered chelate ring in the equatorial plane. The N atoms from two donor ligands are axially coordinated to the Ni atom.


1983 ◽  
Vol 38 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Bernt Krebs ◽  
Marita Hucke ◽  
Michael Hein ◽  
Andreas Schäffer

Abstract The monomeric SeOCl3- ion, which can be prepared as the tetraphenylarsonium salt from SeOCl2 and As(C6H5)4Cl, was structurally characterized by a low-temperature single crystal X-ray diffraction analysis. [As(C6H5)4]SeOCl3 is monoclinic, space group P21/c, with a = 9,332(3), b = 13,761(4), c = 18,985(6) Å, β = 110,97(3)° (at -135 °C), Z = 4; it contains a novel type of ψ-trigonal bipyramidal oxotrichloroselenate(IV) anion which is not associated to dimers or polymer chains as in known structures. The equatorial positions are occupied by doubly bonded oxygen (Se-O 1,601(3) Å) and by one Cl(Se-Cl 2,234(1) Å), the axial Se-Cl bonds (2,430(1) and 2,475(1) Å) being significantly longer. [N(C2H5)4]SeOCl3, which was obtained as crystals by oxidation of trichloroselenate(II), is triclinic, space group P1̄, with a = 10,607(3), b = 8,950(2), c = 8,862(2) Å, α = 119,79(2)°, β = 101,07(2)°, γ = 96,28(2)°, Z = 2. The X-ray structure analysis shows the anions to be present as centrosymmetric dimers Se2O2Cl62- like in the [P(C6H5)4]+ salt, with two tetragonal SeOCl4 pyramids linked through a Cl···Cl edge and the lone pairs trans to the axial Se-O bonds (1,589(4) Å). Se-Cl bond lengths are 2.270(1) and 2,351(2) Å (terminal); 2,698(1) and 2,920(1) Å (bridging). The results show that the nature of the reaction products of the Lewis acid SeOCl2 with halogenides as bases changes very sensitively with small variations in cations and environment. The vibrational spectra are discussed.


1998 ◽  
Vol 51 (3) ◽  
pp. 219 ◽  
Author(s):  
Ian R. Whittall ◽  
Mark G. Humphrey ◽  
David C. R. Hockless

The structures of Ni(C≡CR)(PPh3)(η-C5H5) (R = Ph (1), C6H4-4-NO2 (2), 4-C6H4C6H4-4′-NO2 (3), (E)-4-C6H4CH=CHC6H4-4′-NO2 (4), 4-C6H4C≡CC6H4-4′-NO2 (5), 4-C6H4N=CHC6H4-4′-NO2 (6)) have been determined by single-crystal X-ray diffraction studies, refining by full-matrix least-squares analysis. For (1), crystals are triclinic, space group P-1, with a 10·094(2), b13·429(3), c 18·835(5) Å,α 103·24(2), β 91·50(2), γ 90·10(2)°, Z 4, 5844 unique reflections (595 parameters), converging at R 0·033 and Rw 0·024. For (2), crystals are orthorhombic, space group Pna21, with a 16·799(2), b 8·681(2), c 17·485(2) Å, Z 4, 1774 unique reflections (325 parameters), converging at R 0·031 and Rw 0·029. For (3), crystals are monoclinic, space group P 21/c, with a 11·140(3), b 18·282(4), c 15·296(2) Å, β 105·18(2)°, Z 4, 3132 unique reflections (397 parameters), converging at R 0·039 and Rw 0·024. For (4), crystals are monoclinic, space group P 21/n, with a 12·929(7), b 16·953(8), c 15·601(7) Å, β 112·55(3), Z 4, 3023 unique reflections (397 parameters), converging at R 0·039 and Rw 0·025. For (5), crystals are monoclinic, space group P 21/n, with a 12·710(5), b 16·882(3), c 15·693(4) Å, β 111·37(3)°, Z 4, 3216 unique reflections (397 parameters), converging at R 0·035 and Rw 0·030. For (6), crystals are monoclinic, space group P 21/n, with a 12·594(1), b 16·936(2), c 15·611(1) Å, β 112·476(5)°, Z 4, 3564 unique reflections (397 parameters), converging at R 0·038 and Rw 0·041. For structurally characterized 18-electron (cyclopentadienyl)nickel(II) acetylide complexes, statistically insignificant decreases in the average Ni-C(1) distance and trans influence and an increase in the average C(1)-C(2) parameter are observed on introduction of an acceptor substituent at the alkynyl ligand.


2008 ◽  
Vol 63 (2) ◽  
pp. 139-142 ◽  
Author(s):  
Sevim Hamamci ◽  
Veysel T. Yilmaz ◽  
Orhan Büyükgüngör

Two new complexes [Ag(sac)(aepip)] (1) and [Ag(sac)(hepip)] (2) have been obtained by the reaction of AgNO3 with Na(sac)・2H2O (sac = saccharinate) in the presence of N-(2-aminoethyl)piperidine (aepip) and N-(2-hydroxyethyl)piperidine (hepip), and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group C2 and triclinic space group P1, respectively. In both complexes, silver( I) is tricoordinated. The sac ligand is N-coordinated, while aepip and hepip behave as N-N and N-O bidentate chelating ligands, respectively. The pip rings of both aepip amd hepip ligands adopt typical ‘chair’ conformation. The individual molecules are linked into one-dimensional chains by two N-H···O hydrogen bonds in 1, and one O-H···O hydrogen bond in 2. TG-DTG curves illustrated that the endothermic elimination of aepip and hepip ligands takes place in the early stages of thermal decomposition, while that of the sac moiety occurs exothermically at higher temperatures to give metallic silver


1999 ◽  
Vol 54 (10) ◽  
pp. 1222-1228 ◽  
Author(s):  
S. Strueß ◽  
W. Preetz

By treatment of fac-[ReCl3I3]2- with (SeCN)2 indichloromethane fac-[ReCl3(NCSe)3]2- (1), mer-[ReCl3(NCSe)2cis (SeCN)]2- (2) and mer-[ReCl3I(NCSe)2cis]2- (3) are formed which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structures of mer-(Ph-P)2[ReCl3(NCSe)2cis(SeCN)] (triclinic, space group Pl̅, a = 16.099(1), b = 16.729(3), c =21.026(2) Å, α = 70.194(10), ß = 73.958(10), γ = 83.929(10)°, Z = 4) and mer-(n-Bu4N)2[ReCl3|(NCSe)2cis] (monoclinic, space group P21/c, a = 11.838(1), b = 12.796(2), c = 30.767(2) Å, ß = 97.419(6)°, Z = 4) have been determined by single crystal X-ray diffraction analysis. Based on the molecular parameters of the X-ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu4N) salts have been assigned by normal coordinate analysis. The valence force constants are fd(ReN) = 1.79 (1), 1.71 (2), 1.71 (3) and fd(ReSe) = 1.15 (2) mdyn/Å.


1992 ◽  
Vol 47 (1) ◽  
pp. 139-143 ◽  
Author(s):  
Mohamed A. S. Goher ◽  
Morsy A. M. Abu-Youssef ◽  
Franz A. Mautner

The structures of mer-Cr(py)3(N3)3 (1) and polymeric NaCr(py)4(N3)4 (2) were determined by X-ray crystallography. Crystal data; 1, C15H15N12Cr, triclinic, space group P1̄, a = 895.3(2), b = 999.1(3), c = 1269.9(5) pm , α = 106.76(3), β = 96.69(3), γ = 116.30(2)°, V = 943.8(6) · 106 pm3, Z = 2 and Rw = 0.038 for 1736 observed MoKα diffractometer data; 2, C20H20N16CrNa, monoclinic, space group C2/c, a = 1561.2(3), b = 1028.8(2), c = 1573.6(4) pm, β = 90.70(2)°, V = 2 527.3(9) · 106 pm3, Z = 4 and = 0.033 for 1272 MoKα diffractometer data.The coordination around the chromium (III) ion in the discrete molecules of 1 is six-coordinate with mean distances Cr-N(py) of 210.2(4) pm and Cr-N(N3) of 200.8(4) pm. The terminal azido ligands are almost linear and asymmetric, the N-N bonds nearer to the metal (118.8(6) to 120.5(7) pm) being significantly longer than the terminal ones (114.7(7) to 115.5(7) pm). In compound 2, each chromium or sodium cation is six-coordinated by four azido groups and two pyridine molecules. The azido groups act as μ(1,3) bridging ligands between chromium and sodium octahedra to form a three-dimensional network structure. The chromium atoms are trans-coordinated by the pyridine ligands whereas the sodium cations are cis-coordinated.


1990 ◽  
Vol 45 (7) ◽  
pp. 995-999 ◽  
Author(s):  
Karin Ruhlandt-Senge ◽  
Ulrich Müller

The title compounds were obtained from NiS + PPh4Cl + HCl in dichloromethane, from NiCl2 and PPh4Cl and from NiCl2 + Na2S + 15-crown-5 in acetonitrile or CH2Cl2, respectively. Their crystal structures were determined by X-ray diffraction. (PPh4)2[NiCl4]: monoclinic, space group C 2/c, Z = 4, a = 1094.9(3), b = 1946.1(4), c = 2033.5(5) pm, β = 91.48(3)°; R = 0.07 for 2895 unique observed reflexions. [Na-15-crown-5]2[NiCl4]: triclinic, space group P1̄, Z = 2, a = 987.6(1), b = 998.0(1), c = 1779.9(2) pm, α = 104.17(1), β = 95.43(1), γ = 109.95(1)°; R = 0.090 for 4155 unique observed reflexions. In both cases, the [NiCl4]2- ions have distorted tetrahedral structures. With PPh4+ as the cation the distortion corresponds to a twisted tetrahedron which fulfils the point symmetry D2, the deviation from a flattened D2d-tetrahedron being small. In (PPh4)2[NiCl4] cations and anions alternate in layers parallel to (001). In [Na-15-crown-5]2[NiCl4] two of the Cl atoms of the anion are coordinated to sodium ions; one of the crown ether molecules shows positional disorder.


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