Steric Modification of Metal-Phosphorus Bond Lengths: the Preparation, Characterization and CrystalStructures of mer-trans-(PPri3)2(Pme2Ph)-Cl-cis-H2IrIII(1) and mer-trans-(PPri3)2(PMe2Ph)H3IrIII

1995 ◽  
Vol 48 (6) ◽  
pp. 1183 ◽  
Author(s):  
EJ Ditzel ◽  
GB Robertson

The syntheses and subsequent characterization of the complexes mer -trans-(PPri3)2(Pme2Ph)-Cl-cis-H2IrIII(1) and mer-trans-(PPri3)2(PMe2Ph)H3IrIII (2) by n.m.r. and by low temperature (153�5 K) X-ray diffraction analyses are reported. Crystals of (1) are monoclinic, space group P21/c with a 19.277(2), b 9.020(1), c 17.657(2) Ǻ, β 101.40(1)° and Z 4. Crystals of (2) are orthorhombic, space group P212121, with a 19.373(3), b 18.724(2), c 8.113(1) Ǻ and Z 4. Full-matrix least-squares analyses converged with R = 0.027 and wR = 0.031 for (1) (3243 reflections), and R = 0.030 and wR = 0.038 for (2) (2892 reflections). Consistent with previous observation, the unit increase in chloride content (in place of hydride) in (1) is accompanied by a global lengthening of 0.036 Ǻ (av.) in the Ir -P bond lengths cf. those in (2). Also, because of increased steric crowding (two PPri3 ligands in place of two Pme2Ph), the Ir-PMe2Ph bond in (1) is 0.019(2) Ǻ longer than the chemically equivalent bond in mer-(PMe2Ph)3Cl-cis-H2IrIII. In previously reported complexes in this series metrically similar increases in Ir-PMe2Ph distances result from the replacement of just one Pme2Ph ligand by PPri3.

1988 ◽  
Vol 41 (3) ◽  
pp. 283 ◽  
Author(s):  
GB Robertson ◽  
PA Tucker

The structures of two crystalline modifications of mer -(Pme2Ph)3H-cis-Cl2IrIII, (1), have been determined from single-crystal X-ray diffraction data. Modification (A) is monoclinic, space group P21/c with a 12.635(1), b 30.605(3), c 14.992(2)Ǻ, β 110.01(2)° and Z = 8. Modification (B) is orthorhombic, space group Pbca with a 27.646(3), b 11.366(1), c 17.252(2)Ǻ and Z = 8. The structures were solved by conventional heavy atom techniques and refined by full-matrix least- squares analyses to conventional R values of 0.037 [(A), 8845 independent reflections] and 0.028 [(B), 5291 independent reflections]. Important bond lengths [Ǻ] are Ir -P(trans to Cl ) 2.249(1) av. (A) and 2.234(1) (B), Ir -P(trans to PMe2Ph) 2.339(2) av. (A) and 2.344(1), 2.352(1) (B), Ir-Cl (trans to H) 2.492(2), 2.518(2) (A) and 2.503(1) (B) and Ir-Cl (trans to PMe2Ph)2.452(2) av. (A) and 2.449(1)(B). Differences in chemically equivalent metal- ligand bond lengths emphasize the importance of non-bonded contacts in determining those lengths.


1992 ◽  
Vol 47 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Anja Edelmann ◽  
Sally Brooker ◽  
Norbert Bertel ◽  
Mathias Noltemeyer ◽  
Herbert W. Roesky ◽  
...  

Abstract The Molecular Structures of [2,4,6-(CF3)3C6H2S]2 (1) [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2 (3) have been determined by X-ray diffraction. Crystal data: 1: orthorhombic, space group P212121, Z = 4, a = 822.3(2), b = 1029.2(2), c = 2526.6(5) pm (2343 observed independent reflexions, R = 0.042); 2: orthorhombic, space group Iba 2, Z = 8, a = 1546.5(2), b = 1578.4(2), c = 1483.9(1) pm (2051 observed independent reflexions, R = 0.030); 3: monoclinic, space group P 21/c, Z = 4, a = 1118.7(1), b = 1536.5(2), c = 1492.6(2) pm, β = 98.97(1)° (3033 observed independent reflexions, R = 0.025).


2019 ◽  
Vol 74 (4) ◽  
pp. 381-387
Author(s):  
Michael Zoller ◽  
Jörn Bruns ◽  
Gunter Heymann ◽  
Klaus Wurst ◽  
Hubert Huppertz

AbstractA potassium tetranitratopalladate(II) with the composition K2[Pd(NO3)4] · 2HNO3 was synthesized by a simple solvothermal process in a glass ampoule. The new compound crystallizes in the monoclinic space group P21/c (no. 14) with the lattice parameters a = 1017.15(4), b = 892.94(3), c = 880.55(3) Å, and β = 98.13(1)° (Z = 2). The crystal structure of K2[Pd(NO3)4] · 2HNO3 reveals isolated complex [Pd(NO3)4]2− anions, which are surrounded by eight potassium cations and four HNO3 molecules. The complex anions and the cations are associated in layers which are separated by HNO3 molecules. K2[Pd(NO3)4] · 2HNO3 can thus be regarded as a HNO3 intercalation variant of β-K2[Pd(NO3)4]. The characterization is based on single-crystal X-ray and powder X-ray diffraction.


1997 ◽  
Vol 50 (9) ◽  
pp. 903 ◽  
Author(s):  
Trevor W. Hambley ◽  
Walter C. Taylor ◽  
Stephen Toth

Four novel norditerpenoids were isolated from a new encrusting sponge, conveniently labelled Aplysilla pallida. The structures of aplypallidenone (1), aplypallidoxone (2), aplypallidione (3) and aplypallidioxone (4) were elucidated by spectroscopic studies and the crystal structures of aplypallidenone and aplypallidoxone have been determined by X-ray diffraction methods. The structure of (1) was refined to a residual of 0·040 for 1665 independent observed reflections and the structure of (2) was refined to a residual of 0·031 for 1699 independent observed reflections. The crystals of (1) are orthorhombic, space group P212121, a 7·728(2), b 10·838(4), c 24·880(5) Å, Z 4. Those of (2) are monoclinic, space group C 2, a 23·927(7), b 6·674(2), c 14·033(3) Å, Z 4.


1995 ◽  
Vol 73 (9) ◽  
pp. 1520-1525
Author(s):  
Luciano Antolini ◽  
Ugo Folli ◽  
Dario Iarossi ◽  
Adele Mucci ◽  
Silvia Sbardellati ◽  
...  

The crystal structures of the title compounds were determined by single crystal X-ray diffraction techniques. The molecule of the Z isomer, which crystallizes in the monoclinic space group C2/c with Z = 4 in a cell of dimensions a = 14.891 (2), b = 10.780(2), c = 8.769(1) Å, β = 97.47(2)°, V = 1395.7(7) Å3 has crystallographic twofold symmetry. The E form crystallizes in the orthorhombic space group Pbca with a = 11.730(1), b = 6.932(1), c = 16.841(1) Å, V = 1369.4(2) Å3 and Z = 4. Its molecules have crystallographically dictated [Formula: see text] symmetry. In both isomers the phenyl rings are roughly perpendicular to the average ethylene plane. The atoms characterizing this plane show significant deviations from planarity in the Z isomer. Marked bond-angle distortions at the ethene carbons of both structures are observed. The 1H and 13C NMR spectra of the compounds were measured and, particularly in the case of the 1H chemical shifts, fall into two quite separate spectral regions. At low temperature, two conformational isomers, those with different relative orientation of the C—Cl bonds of the phenyl rings, are observed in the spectrum of each compound. Keywords: chlorostilbenes, overcrowded molecules. X-ray structure, conformations, NMR spectroscopy.


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.


1991 ◽  
Vol 46 (4) ◽  
pp. 337-343 ◽  
Author(s):  
Da Zhang ◽  
Shi-Qi Dou ◽  
Alarich Weiss

Abstract The molecular motion in (CH3)3XCl, X = Sn and Pb has been investigated by measurement of the second moment M2(1H) as function of temperature in the range 95 < T,/K<345. The methyl groups in both compounds rotate freely over the whole temperature range studied. In (CH3)3SnCl the C'3-rotation of (CH3)3Sn-group about the Sn CI axis sets in above 273 K. To explain the NMR and INS results, the crystal structures of (CH3)3PbCl and CH3SnBr3 were determined by single X-ray diffraction. (CH3)3PbCl crystallizes in a monoclinic space group C32-C2, a = 1276.7(3) pm, b = 982.3(3) pm, c = 547.0(2) pm, ß = 91.12(1)°; Z = 4, R = 0.035. CH3SnBr3 crystallizes in an orthorhombic space group D162h-Pnma, a = 643.0(3) pm, b= 1005.3(4) pm, c= 1148.0(4) pm; Z = 4, R =0.057


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.


1996 ◽  
Vol 49 (4) ◽  
pp. 527 ◽  
Author(s):  
PT Gulyas ◽  
TW Hambley ◽  
PA Lay

The crystal structure of [ Ru ( terpy )( bpy )( pz )] (PF6)2 has been determined by X-ray diffraction methods and refined to a residual of 0.046 for 1855 independent observed reflections. The crystals are monoclinic, space group P 21/a, a 16.836(7), b 10.778(5), c l9.342(5) Ǻ, β 115.11(3)°. The coordination geometry around the ruthenium(II) ion is distorted octahedral, with the various Ru -N bond lengths indicative of considerable interligand steric strain. The Ru -N pyrazine bond is the longest within the structure, consistent with other evidence that n back-bonding to pyrazine is weak in the complex.


1987 ◽  
Vol 42 (9) ◽  
pp. 1107-1109 ◽  
Author(s):  
Frank Edelmann ◽  
Claudia Spang ◽  
Mathias Noltemeyer ◽  
George M. Sheldrick ◽  
Nayla Keweloh ◽  
...  

(PhAsNSN)2 (1) reacts with M(CO)4(C7H8) (M = a Cr. b Mo) to yield (PhAsNSN)2M(CO)4 (2). 2a and 2b are dark red air stable complexes. 2b was characterized by X-ray diffraction. Crystals of 2b are monoclinic, space group C2/c, with a = 2884.7(4). b = 1166.2(2), c = 1344.1(2) pm, fβ = 104.81(2)° and Z = 8. The molecule exhibits approximate mm (C2v) symmetry with mean bond lengths: Mo-As 255.1. Mo-C 201.8. As-N 186.2 and S -N 152.8 pm.


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