Crystal and Molecular Structures of the Functional Lithium Cyclopentadienides [Li(tmeda)][R2PCMe2C5H4], R = Ph, Me

2000 ◽  
Vol 55 (11) ◽  
pp. 1005-1010 ◽  
Author(s):  
Ulrich Jürgen Bildmann ◽  
Martin Winkler ◽  
Gerhard Müller Fachbereich

The crystal and molecular structures of the phosphinomethyl-substituted lithium cyclopentadienides [Li(tmeda)][R2PCMe2C5H4], R = Ph (1), Me (2) (tmeda = N,N,N',N'-tetramethylethylenediamine) were determined as their tmeda adducts on the basis of low temperature single crystal X-ray diffraction. (Crystal data: 1: monoclinic, space group P21/n, a = 8.511(5), b = 11.936(2), c = 24.20(1) Å, β = 90.02(3)°, Z = 4.2: monoclinic, space group P21/n, a = 10.887(2), b = 13.326(2), c = 13.131(2) Å, β= 92.872(6)°, Z = 4). In both compounds lithium has a slightly distorted 17 coordination to the cyclopentadienide (Cp) ring. There are no interactions between lithium and the phosphine donors in the solid state as the phosphinomethyl substituents are oriented to the other side of the Cp ring for steric reasons. The isopropene-substituted lithium cyclopentadienide, which is formed as a by-product in the synthesis of phosphinomethyl cyclopentadienides containing a CMe2 bridge, was also structurally characterized as its tmeda adduct [Li(tmeda)][H2C=CMeC5H4] (3). (Crystal data: monoclinic, P21/c, a = 8.00(2), b = 16.701(2), c = 11.942(6) Å, β= 112.68(7)°, Z = 4). As in 1 and 2, lithium is η5 -coordinated to the Cp ring, and there is no interaction of the functional group (isopropene) with lithium.

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).


Author(s):  
G. D. Nigam ◽  
G. Mattern ◽  
R. Fröhlich

AbstractThe crystal and molecular structures of 1-(m-nitrophenyl)-2,2-dicarboethoxy-3-phenyl-pyrrolidin-5-one (I) and 1-(p-chlorophenyl)-2,2-dicarboethoxy-3-phenyl-pyrrolidin-5-one (II) have been determined by X-ray diffraction methods. (I) crystallizes in the monoclinic space group


Author(s):  
G. Dewald ◽  
M. Hanack ◽  
E.-M. Peters ◽  
L. Walz

AbstractThe crystal and molecular structures of dimorphic 10,10′-(1,4-phenylene-dimethylidene)-bis-9,10-H-anthracenone (1) have been determined using X-ray diffraction data. The compound crystallizes either in the monoclinic space groupSince all non-hydrogen atoms are of pure


1993 ◽  
Vol 48 (12) ◽  
pp. 1821-1827 ◽  
Author(s):  
Ilpo Mutikainen ◽  
Hannu Elo ◽  
Pirkko Tilus

The first study on the crystal and molecular structures of basic forms of bis(amidinohydrazones) is reported. The structures of the free base and the monohydrochloride salt of the antileukemic agent glyoxal bis(amidinohydrazone) (GBG) were determined by single crystal X-ray diffraction and were refined to R-values of 0.038 and 0.040, respectively. These structures are of special interest because recent results indicate that, in contrast to previous assumptions, the free base may be the actual antileukemic form of bis(amidinohydrazones) and that the monocation form is the predominant species of antileukemic bis(amidinohydrazones) at physiological conditions. In the crystals of the free base as well as in those of the monohydrochloride salt, GBG was found to exist solely in the all-trans configuration of the chain and to consist of one of the three possible geometrical isomers only. In the solid state, GBG free base consists solely of the endiamine tautomer instead of the 'classical’ carboximidamide tautomer, as does also the non-protonated part of GBG monocation in the monohydrochloride salt. Proton NMR measurements indicated that the free base consists of the endiamine tautomer also in dimethyl sulfoxide solution. In the solid state, both of the compounds studied consist of stacks of planes. In the case of the free base, the stacks are crisscross to each other. The distance between the mean planes of the molecules or the monocations is approximately 3.5 Å. The crystals of the monohydrochloride salt contain one molecule of water per each GBG monocation. In both compounds studied, the molecules in the crystals are held together by very extensive hydrogen bond networks and by the interaction of delocalized π-electrons. The crystal of C4H10N8 is monoclinic, space group C2/c with a = 15.874(6), b = 6.972(4), c = 7.8l3(5)Å, β = 90.34(4)° and Z = 4. The crystal of C4H13N8OC1 is monoclinic, space group P21/n with α = 7.010(3), b = 22.307(9), c = 7.028(3)Å, β = 66.33(3)° and Ζ = 4.


1978 ◽  
Vol 31 (4) ◽  
pp. 781 ◽  
Author(s):  
R Mason ◽  
GR Scollary

The crystal and molecular structures of two rhodium(I) complexes with long-chain alkyne- or alkene-α,ω-diyldiphosphines have been determined by single-crystal X-ray diffraction techniques. RhCl(CO){But2P(CH2)4C≡C(CH2)4PBut2} crystallizes in the orthorhombic space group Pna21 with a 21.991 (2), b 11.915(1), c 11.890(1) Ǻ and Z 4. The structure was refined by least-squares methods to a conventional R factor of 0.097 for 1768 independent reflections (Mo Kα diffraction data). The rhodium ion is in a square-planar coordination geometry with trans-phosphorus atoms; the unsaturated (alkynyl) group is not bonded to the rhodium. Crystals of RhCl{But2P(CH2)2CH=CH(CH2)2- PBut2} are monoclinic, space group P21/c, a 20.783(12), b 8.580(4), c 14.799(9) Ǻ, β 100.70(2)°, Z 4. The structure analysis has converged to R 0.069 for 1417 reflections (Mo Kα diffractometry); the coordination geometry of the rhodium is again planar with the ethylenic group occupying a single bonding site. The effect of ring size on the rhodium-phosphorus bond lengths is discussed.


2021 ◽  
Vol 12 (2) ◽  
pp. 216-221
Author(s):  
Joana Hipolito ◽  
Luis Alves ◽  
Ana Martins

New Ti(IV), Zr(IV) and Al(III) salen-based complexes of formulae [(L)TiCl2], 2, [(L)ZrCl2], 3, and [(L){Al(CH2CH(CH3)2)2}2], 4, where L = meso-(R,S)-diphenylethylene-salen, were synthesized in high yields. [(L){Al(CH2CH(CH3)2)2}2] is a bimetallic complex that results from the reaction of H2L with either 1 or 2 equivalent of Al(CH2CH(CH3)2)3. The solid-state molecular structures of compounds 2 and 4·(C7H8) were obtained by single-crystal X-ray diffraction. Crystal data for C44H54Cl2N2O2Ti, (2a): monoclinic, space group C2/c (no. 15), a = 27.384(1) Å, b = 12.1436(8) Å, c = 28.773(2) Å, β = 112.644(2)°, V = 8830.6(9) Å3, Z = 8, μ(MoKα) = 0.350 mm-1, Dcalc = 1.146 g/cm3, 26647 reflections measured (5.204° ≤ 2Θ ≤ 50.7°), 8072 unique (Rint = 0.0967, Rsigma = 0.1241) which were used in all calculations. The final R1 was 0.0640 (I > 2σ(I)) and wR2 was 0.1907 (all data). Crystal data for C62H72Cl2N2O2Ti (2b): monoclinic, space group P21/c (no. 14), a = 19.606(1) Å, b = 12.793(1) Å, c = 23.189(2) Å, β = 105.710(4)°, V = 5599.0(7) Å3, Z = 4, μ(MoKα) = 0.291 mm-1, Dcalc = 1.182 g/cm3, 37593 reflections measured (3.65° ≤ 2Θ ≤ 50.928°), 10304 unique (Rint = 0.0866, Rsigma = 0.1032) which were used in all calculations. The final R1 was 0.0593 (I > 2σ(I)) and wR2 was 0.1501 (all data). Crystal data for C67H97Al2N2O2 (4·(C7H8)): triclinic, space group P-1 (no. 2), a = 10.0619(9) Å, b = 16.612(2) Å, c = 21.308(2) Å, α = 67.193(5)°, β = 78.157(6)°, γ = 77.576(5)°, V = 3176.8(6) Å3, Z = 2, μ(MoKα) = 0.088 mm-1, Dcalc = 1.063 g/cm3, 42107 reflections measured (5.382° ≤ 2Θ ≤ 51.624°), 12111 unique (Rint = 0.0624, Rsigma = 0.0706) which were used in all calculations. The final R1 was 0.0568 (I > 2σ(I)) and wR2 was 0.1611 (all data). The solid-state molecular structure of [(L){Al(CH2CH(CH3)2)2}2] reveals that both metal centres display a slightly distorted tetrahedral geometry bridged by the salen ligand. Both [(L)TiCl2] and [(L)ZrCl2] complexes display octahedral geometry with trans-chlorido ligands.


1982 ◽  
Vol 35 (7) ◽  
pp. 1311 ◽  
Author(s):  
MA Bennett ◽  
K Ho ◽  
JC Jeffery ◽  
GM Mclaughlin ◽  
GB Robertson

Crystal and molecular structures of the title compounds have been determined from three dimensional X-ray diffraction data recorded on a four-circle diffractometer. Crystals of the acetyl complex, trans-PtCl(COMe)(PMePh2)2,(1), are monoclinic, space group P2,1/c, with a 12.9709(5), b 11.1024(5), c 277535(9) Ǻ, β 94.75(1)° and Z 6. Crystals of the trifluoroacetyl complex, trans-PtCl(COCF3)- (PMePh2)2, (2), are monoclinic, space group P21/n (non-standard setting of P21c), with a 11.4246(7), b 15.5750(7), c 15.4200(8) Ǻ, β 90.54(1)° and Z 4. For (I), with Z 6, the unit cell contains one set of four equivalent molecules in the general equipoint and one set of two equivalent (disordered) molecules located at inversion centres. The four molecules in (2) comprise a single equivalent set in the general equipoint. Least-squares analyses converge with R 0.042 for (1) (5696 unique data) and R 0.025 for (2) (3933 unique data). Molecules of both complexes exhibit small deformations from planar towards tetrahedral platinum geometry; the acyl and coordination planes are approximately orthogonal. The phosphine substituents in (2) and in the 'general' molecules in (1) are approximately eclipsed, and approximately eclipse the Pt-C (acetyl) bonds. In the 'special' molecules in (1) the phosphines are constrained to adopt the mutually staggered conformation found in the alkyl analogues trans-PtClR(PMePhM2)2 (R = Me, CF3, C2F2). Important comparative lengths in (1) (general molecule) and in (2) (in square brackets) are: Pt-C 2.028(6) [1.960(4)] A, Pt-Cl 2.430(2) [2.390(1)] Ǻ, Pt-P 2.301(2), 2.297(2) [2.316(1), 2.321(1)] A, C-O 1.182(8) [1.210(5)] 8, and C C (acetyl) 1.488(10) [1.547(6)] A. The trifluoroacetyl ligand forms a shorter and presumably stronger bond with platinum, and exerts a larger cis- and a smaller trans-influence than the acyl ligand. The smaller trans-influence of the trifluoroacetyl ligand is consistent with the expectation from platinum-chlorine stretching frequencies (v(Pt-Cl)).


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.


1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.


1992 ◽  
Vol 45 (2) ◽  
pp. 429 ◽  
Author(s):  
AT Baker ◽  
MT Emett

The structures of [Pt(S2CN(C2H5)2)2] (1) and [Pt(S2CN(C2H4OH)2)2] (2) have been determined by single-crystal X-ray diffractometry. Compound (1) crystallizes in the tetragonal space group P42/n, a 16.4692(10),c 6.2160(6) � (Z = 4); R was 0.029 for 1012 observed reflections. Compound (2) is monoclinic, space group Pc, a 6-0663(11), b 1.1784(15), c 12.5740(21) � ,β92.569(8)� (Z = 2); R was 0.019 for 1573 observed reflections. The presence of electron-withdrawing groups in the ligands of (2) appears to have little effect on the Pt-S distances but causes an increase in the C-N bond length, with the C-N bond lengths being significantly different at the 2 σ level.


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