Synthesis and structure of the picrate salt of 2,2'-bis[2N-(1,1,3,3-tetramethylguanidino)]biphenyl

Pruszyński, Przemysław; Leffek, Kenneth T.; Borecka, Bozena; Cameron, T. Stanley

doi:10.1107/s010827019200101x

Cited by 24 publications

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“…1. The three bonds between the central carbon (Cl) of the guanidinium group and the three nitrogen atoms are not of equal length in this dication, contrary to the finding in our previous structure determination of a protonated biphenylTMG compound (8) …”

Section: The Structure Ofcontrasting

confidence: 53%

“…Although the angles between the bonds to the C(1) and N(2) atoms are all close to 120°, the torsional angles are quite large. The bonds from N(2) to the two rings are at an angle of about 50-55" to those from C(l) to the two methylated nitrogens, which is larger than the angle of 32-33" found in a phenyltetramethylguanidinium ion (8 equivalence of the methyl groups in the 'H nmr spectrum; the general lack of symmetry in the molecule is confirmed by the 25 resonance signals observed in the 13c nmr spectrum.…”

Section: The Structure Ofmentioning

confidence: 68%

“…As part of our study (6,7) of the reactions of substituted 2-N-phenyl-l,l,3,3-tetramethylguanidine bases (TMG) and the structure of the guanidinium ion (8), we investigated the reaction of 2-N-phenylTMG 4 with 2,6-diphenyl-4H-pyran-4-one 1 in the presence of POC13. Since the imino nitrogen atom in 2-NphenylTMG should react as a tertiary centre, this molecule might be expected to react as a carbon nucleophile to yield the salt of the structure 6, shown in Scheme 1.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and structure of 1,1,3,3,-tetramethyl-2-phenyl-2-(2′,6′-diphenyl-4′-pyrylio)-guanidinium diperchlorate

Galezowski¹,

Bakshi²,

Leffek³

et al. 1994

Can. J. Chem.

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The reaction of 2-N-phenyl-l,l,3,3-tetramethylguanidine with 2,6-diphenylpyran-4-one in the presence of phosphorus oxychloride, followed by treatment with perchloric acid, yields 1,1,3,3-tetramethyl-2-phenyl-2-(2',6'-diphenyl-4'-pyrylio)guanidinium diperchlorate. Crystals of this material are monoclinic, space group P2'/n, a = 14.535(3), b = 13.685(3), c = 23.579(7) A, p = 140.38(2)", R = 0.0633 based on 1691 observed reflections. The substitution of the positively charged pyrylio group on one of the three nitrogen atoms of the guanidinium cation disrupts the symmetry of the distribution of the positive charge on the nitrogen atoms. The two C-N bonds of the central carbon atom of the guanidinium ion to the two methylated nitrogen atoms show more double-bond character than that to the nitrogen carrying the pyrylio group.

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Section: The Structure Ofcontrasting

confidence: 53%

Section: The Structure Ofmentioning

confidence: 68%

Section: Introductionmentioning

confidence: 99%

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Synthesis and structure of 1,1,3,3,-tetramethyl-2-phenyl-2-(2′,6′-diphenyl-4′-pyrylio)-guanidinium diperchlorate

Galezowski¹,

Bakshi²,

Leffek³

et al. 1994

Can. J. Chem.

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“…In this work we examine d 8 Ni complexes of the three bisguanidines btmgb, [18] btmgn, [2] and btmgbp [19] , which exhibit a weaker reduction potential than ttmgb (see Figure S1 in the Supporting Information). All of these complexes represent examples of tetrahedrally coordinated Ni complexes in an open-shell configuration.…”

Section: Introductionmentioning

confidence: 99%

On the Electronic Structure of Ni^II Complexes That Feature Chelating Bisguanidine Ligands

Roquette

Maronna

Peters

et al. 2010

Chemistry A European J

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In this work we report on the syntheses and properties of several new Ni complexes featuring the chelating bisguanidines bis(tetramethylguanidino)benzene (btmgb), bis(tetramethylguanidino)naphthalene (btmgn), and bis(tetramethylguanidino)biphenyl (btmgbp) as ligands. All complexes were structurally characterized by single-crystal X-ray diffraction and quantum chemical calculations. A detailed inspection of the magnetic susceptibility of [(btmgb)NiX(2)] and [(btmgbp)NiX(2)] (X=Cl, Br) revealed a linear temperature dependence of chi(-1)(T) above 50 K, which was in agreement with a Curie-Weiss-type behavior and a triplet ground state. Below approximately 25 K, however, magnetic susceptibility studies of the paramagnetic d(8) Ni complexes revealed the presence of a significant zero-field splitting (ZFS) that results from spin-orbit mixing of excited states into the triplet ground state. The electronic consequences that might arise from the mixing of states as well as from a possible non-innocent behavior of the ligand have been explored by an experimental charge density study of [(btmgb)NiCl(2)] at low temperatures (7 K). Here, the presence of ZFS was identified as one potential reason for the flat angle-spherical Cl-Ni-Cl deformation potential and the distinct differences between the angle-spherical X-Ni-X valence angles observed by experiment and predicted by DFT. An analysis of the topology of the experimentally and theoretically derived electron-density distributions of [(btmgb)NiCl(2)] confirmed the strong donor character of the bisguanidine ligand but clearly ruled out any significant non-innocent ligand (NIL) behavior. Hence, [(btmgb)NiCl(2)] provides an experimental reference system to study the mixing of certain excited states into the ground state unbiased from any competing NIL behavior.

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“…of 0.994. This relationship is complementary to the phenylTMG series previously published (1) and gives a range of bases in acetonitrile from a pK,, of 3.0 up to 23.9 (for DBU (1) It is interesting to note that all the bases fall on the same correlation line despite the fact that the aminopyridine bases are protonated on the ring nitrogen atom, while the pyridylTMG bases are protonated on the N-2 atom of the T M G group, although no doubt considerably delocalized onto the N-1 and the N-2 atoms (9). Thus the solvent effect does not depend on the environment of the proton in the conjugate acid of the base, nor does it depend upon specific solvation of the picrate anion, since Coetzee and Padmanabhan (2) …”

Section: 133-tetramethylguanidines Was Measured (1) In Order Tomentioning

confidence: 99%

Basicity of substituted 2-pyridyl-1,1,3,3-tetramethylguanidines and aminopyridines in acetonitrile and water solvents

Foroughifar¹,

Leffek²,

Lee³

1992

Can. J. Chem.

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NASER FOROUGHIFAR, KENNETH T. LEFFEK, and YONG GU LEE. Can. J. Chem. 70, 2856Chem. 70, (1992. A series of substituted 2-pyridyl-1,1,3,3-tetramethylguanidines has been synthesized and the pK, of each has been measured in acetonitrile and water solvents, together with the pK, of the corresponding aminopyridine. A relationship between the pK,'s in these two solvents has been derived that allows the estimation of a pK,, in acetonitrile from that in water. The results were fitted to the Hammett equation, giving p = 2.31 + 0.14 and 1.64 2 0.11 for the pyridylguanidines in acetonitrile and water, respectively, and 6.16 ? 0.4 and 5.24 5 0.2 for the aminopyridines in the same solvents.

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Synthesis and structure of the picrate salt of 2,2'-bis[2N-(1,1,3,3-tetramethylguanidino)]biphenyl

Cited by 24 publications

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Synthesis and structure of 1,1,3,3,-tetramethyl-2-phenyl-2-(2′,6′-diphenyl-4′-pyrylio)-guanidinium diperchlorate

Synthesis and structure of 1,1,3,3,-tetramethyl-2-phenyl-2-(2′,6′-diphenyl-4′-pyrylio)-guanidinium diperchlorate

On the Electronic Structure of Ni^II Complexes That Feature Chelating Bisguanidine Ligands

Basicity of substituted 2-pyridyl-1,1,3,3-tetramethylguanidines and aminopyridines in acetonitrile and water solvents

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Synthesis and structure of the picrate salt of 2,2'-bis[2N-(1,1,3,3-tetramethylguanidino)]biphenyl

Cited by 24 publications

References 0 publications

Synthesis and structure of 1,1,3,3,-tetramethyl-2-phenyl-2-(2′,6′-diphenyl-4′-pyrylio)-guanidinium diperchlorate

Synthesis and structure of 1,1,3,3,-tetramethyl-2-phenyl-2-(2′,6′-diphenyl-4′-pyrylio)-guanidinium diperchlorate

On the Electronic Structure of NiII Complexes That Feature Chelating Bisguanidine Ligands

Basicity of substituted 2-pyridyl-1,1,3,3-tetramethylguanidines and aminopyridines in acetonitrile and water solvents

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Product

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On the Electronic Structure of Ni^II Complexes That Feature Chelating Bisguanidine Ligands