The molecular and crystal structure of trans-dichloro(dimethylformamide) (2,6-lutidine)platinum(II)

1980 ◽  
Vol 58 (2) ◽  
pp. 97-101 ◽  
Author(s):  
F. D. Rochon ◽  
P. C. Kong ◽  
R. Melanson

The crystal structure of trans-[Pt(DMF)(2,6-lutidine)Cl2] has been determined by X-ray diffraction. The crystals are orthorhombic, space group Pbca, with a = 11.612(13), b = 26.504(33), c = 9.271(9) Å, and Z = 8. The structure was refined by full matrix least-squares analysis to a conventional R factor of 0.051 and a weighted Rw = 0.044. The coordination around the platinum atom is square planar. The 2,6-lutidine ring is perpendicular to the platinum plane. DMF is bonded to platinum through the oxygen atom. It is planar and makes an angle of 71 ° with the platinum plane. The cis–trans configuration of the [Pt(DMF)(L)Cl2] (L = pyridine derivative) complexes in DMF solution is discussed.

1979 ◽  
Vol 57 (1) ◽  
pp. 57-61 ◽  
Author(s):  
R. Melanson ◽  
F. D. Rochon

The crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2 has been determined by X-ray diffraction. The crystals are orthorhombic, space group P212121, with a = 12.486(6), b = 13.444(7), c = 14.678(11) Å, and Z = 4. The structure was refined by block-diagonal least-squares analysis to a conventional R factor of 0.050 and a weighted Rw = 0.045.The coordination around the platinum atom is square planar. Guanosine is bonded to platinum through N(7). The purine planar ring makes an angle of 62.7° with the platinum coordination plane. The structure is stabilized by hydrogen bonding.


1975 ◽  
Vol 53 (14) ◽  
pp. 2093-2101 ◽  
Author(s):  
Kapil Gurtu ◽  
W. David Chandler ◽  
Beverly E. Robertson

The crystal structure of 2-(2′,6′-dinitrophenoxy)-t-butylbenzene, C16HI5N2O5, has been determined by X-ray diffraction. The crystals are monoclinic, space group P21/c: a = 13.949(9), b = 9.652(6), c = 23.806(12) Å, β = 93.82(5), Z = 8. The integrated intensities of 6811 reflections were recorded with a four circle automated diffractometer at 20 °C; 3334 of these reflections were used in the refinement of the structure to a least-squares weighted residual of 0.057 and a traditional R factor of 0.057.The two crystallographically independent molecules both have the skew-t-butyl-distal conformation, suggesting that the steric effects of the two ortho-nitro groups play a greater role in determining the conformation than does conjugation with the bridging oxygen atom.


1984 ◽  
Vol 62 (12) ◽  
pp. 2657-2660 ◽  
Author(s):  
F. D. Rochon ◽  
P. C. Kong ◽  
R. Melanson

Three types of complexes, trans-[Pt(LH)2Cl2], [Pt(L)2], and [Pt(LH)2(SR)2] where LH = NH2—C(CH3)2(CH2OH) and NH2—C(CH2OH)3 and L are the deprotonated ligands, have been synthesized.The crystal structure of trans-[Pt(NH2—C(CH3)2CH2OH)2Cl2] has been determined by X-ray diffraction methods. The crystals are monoclinic, space group P21/c, with a = 6,282(3), b = 20,901(13), c = 10,769(10) Å, β = 92,64(6)°, and Z = 4. The structure was refined by full-matrix least-squares analysis to a conventional R factor of 0.049 and Rw = 0.042. The coordination around the platinum atom is square planar. The Pt—Cl distances are 2.306(2) and 2.309(3) Å and the Pt—N bonds are 2.060(8) and 2.071 (7) Å. The hydroxyl oxygen atoms are disordered; the disorder is different for each organic ligand. The structure is stabilized by an extensive hydrogen bonding system.


1978 ◽  
Vol 31 (2) ◽  
pp. 411 ◽  
Author(s):  
GR Scollary

A structural analysis of [(η-C5H5)2YMe2AlMe2] has been carried out by X- ray diffraction. Crystals are orthorhombic, space group Pna21, a 17.969(6), b 7.988(4), c 10.870(4) Ǻ, Z 4. The structure has been refined by a full-matrix least-squares procedure to R 0.052 for 663 observed reflections (Mo Kα automatic diffractometry). The structure contains a dimethyl bridge, the average bridging bond distances being 2.58(3) Ǻ for Y-C and 2.10(2) Ǻ for Al-C, and the Y-Al separation is 3.056(6) Ǻ.


1980 ◽  
Vol 58 (4) ◽  
pp. 381-386 ◽  
Author(s):  
F. D. Rochon ◽  
P. C. Kong ◽  
B. Coulombe ◽  
R. Melanson

The interactions between [Pd(dien)Cl]Cl and some nucleosides and nucleotides were studied by nmr. The binding site of guanosine, guanosinemonophosphoric acid, xanthosine, and inosine is N(7). Cytidine is coordinated to palladium through N(3). Adenosinemonophosphate acts as a bidentate, binding two different palladium atoms at N(1) and N(7).The crystal structure of [Pd(dien)(guanosine)](ClO4)2 has been determined by X-ray diffraction. The crystals are orthorhombic, space group P212121, with a = 13.422, b = 14.587, c = 12.432, and Z = 4. The structure was refined by block-diagonal least-squares analysis to a conventional R factor of 0.047 and a weighted Rw = 0.043. The coordination around the palladium atom is square planar. Guanosine is bonded to palladium through N(7). The planar purine ring makes an angle of 63.4° with the palladium coordination plane. The structure is stabilized by hydrogen bonding.


1975 ◽  
Vol 53 (14) ◽  
pp. 2108-2114 ◽  
Author(s):  
Simon P. N. van der Heijden ◽  
W. David Chandler ◽  
Beverly E. Robertson

The crystal structure of 2′-(4′-carbomethoxy-2′-nitrophenylsulfinyl)-1,3,5-trimethylbenzene, C17H17NO5S, has been determined by X-ray diffraction. The crystals are triclinic, a = 9.848(11), b = 7.654(10), c = 12.513(15) Å, α = 107.33(8), β = 100.73(8), γ = 106.53(8)°, [Formula: see text] with Z = 2. The intensities of 3850 independent reflections were measured on a four circle diffractometer; 2985 reflections were used in the refinement to give a final least-squares residual of 0.053 and a traditional R factor of 0.052.Repulsion between the sulfoxide oxygen atom and the nitro oxygen atoms forces the molecule into the twist-nitro-proximal conformation as opposed to the nitro-distal conformation which has been observed for other bridged diphenyls in this series.


1980 ◽  
Vol 58 (7) ◽  
pp. 658-663 ◽  
Author(s):  
Ramanathan Gopal ◽  
W. David Chandler ◽  
Beverly E. Robertson

The structure of (4′-carbomethoxy-2′-nitrophenoxy)benzene, C14H11NO5, has been determined by X-ray diffraction. The crystals are monoclinic, a = 8.880(7), b = 9.792(4), c = 14.820(5), β = 90.07(5), P21/c with Z = 4. The integrated intensities of 2966 independent reflections were measured on a four-circle diffractometer, 2072 of which were used in the refinement to give a final least-squares weighted residual of 0.062 and a conventional R factor of 0.086. The absence of ortho substituents on one ring of the molecule allows it to adopt the twist-nitro-distal conformation. The lengths of the bonds from the unsubstituted ring and the substituted ring to the bridging oxygen atom are 1.409(3) and 1.353(3) Å respectively. The torsional angles about those bonds are 54.6° and 16.5°. The angle subtended at the bridging oxygen atom is 120.0(3)°.The unusual thermal ellipsoids associated with one of the nitro oxygen atoms of this structure and with a nitro oxygen atom of three related structures occur when the nitro substituent is nearly coplanar with the phenyl ring on which it is substituted and also has a neighbouring substituent or bridging group. The unusual thermal ellipsoids then result from repulsive exchange forces.


1979 ◽  
Vol 57 (20) ◽  
pp. 2767-2774 ◽  
Author(s):  
Ramanathan Gopal ◽  
W. David Chandler ◽  
Beverly E. Robertson

The structure of 2-(4′-carbomethoxy-2′-aminophenoxy)-1,3,5-trimethylbenzene, C17H19NO3, has been determined by X-ray diffraction. The crystals are monoclinic, a = 23.895(9), b = 7.821(4), c = 16.641(8) Å, β = 99.26(3), C2/c, Z = 8. The integrated intensities of 3540 independent reflections were measured on a four-circle diffractometer. A total of 2403 of these reflections was used in the refinement to give a final least-squares weighted residual of 0.069 and a conventional R factor of 0.096. The molecule adopts the skew-amino-distal conformation as does the analogous ortho-nitro-substituted compound. The lengths of the bonds from the amino substituted ring and the mesityl ring are 1.404(3) and 1.376(4) Å respectively and the torsional angles about those bonds are ±5.8 and [Formula: see text]. The angle subtended at the bridging oxygen atom is 120.1°. Variations in the endocyclic angles subtended at substituted ring carbon atoms in this and other bridged diphenyls may be understood in terms of a combination of hybridization effects, and the spatial requirements of the bonds to substituents.


1979 ◽  
Vol 32 (2) ◽  
pp. 297
Author(s):  
BW Skelton ◽  
AH White

The crystal structure of the title compound, NaAg(NO2)2, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by full-matrix least squares to a residual of 0.043 for 449 'observed' reflections. Crystals are orthorhombic, space group Fd2d, a 7.913(2), b 10.721(2), c 10.857(3) �, Z 8. The structure is closely related to that of sodium and silver nitrites; the silver environment is dominated by the 'linear' coordination of a nitro group (Ag-N 2.25(2) �) and a 'chelating' pair of oxygen atoms from another NO2- species (Ag-O 2.422(8)�), the O2N-Ag-O2N group containing a crystallographic 2 axis.


1980 ◽  
Vol 33 (2) ◽  
pp. 431 ◽  
Author(s):  
A Farrand ◽  
AK Gregson ◽  
BW Skelton ◽  
AH White

The crystal structure of the title compound, K2Cu(CO3)2, has been determined by single-crystal X-ray diffraction at 295(1) K, and refined by least squares to a residual of 0.027 for 1441 'observed' reflections. Crystals are orthorhombic, space group Fdd2, a 11.425(3), b 17.658(4), c 6.154(2) A, Z 8. The structure comprises potassium cations embedded in an infinite three-dimensional polymeric anionic array of square-planar coordinated copper atoms with bridging carbonate groups [Cu-O 1.934(2), 1.936(2) Ǻ]. Within the latter, the non- coordinating oxygen-carbon bond is shorter [1.259(3) Ǻ] than the other two [1.303(3), 1.307(2) Ǻ] and the O-C-O angle opposite it is correspondingly reduced to 117.1(2)°. The CO3 plane lies at 83.9° to the CuO4 'plane'.


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