Longest CCC Single Bond among Neutral Hydrocarbons with a Bond Length beyond 1.8

2018 ◽  
Author(s):  
Yusuke Ishigaki ◽  
Takuya Shimajiri ◽  
Takashi Takeda ◽  
Ryo Katoono ◽  
Takanori Suzuki
Keyword(s):  
Bond Length ◽  
Single Bond

Notizen: Cyclophanes, XXX The Crystal Structure of [2.4]Paracyclophane at —95°C

1989 ◽  
Vol 44 (7) ◽  
pp. 860-862 ◽  
Author(s):  
Peter G. Jones ◽  
Zissis Pechlivanidis ◽  
Henning Hopf
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Aromatic Ring ◽  
Single Bond ◽  
Orthorhombic Space Group ◽  
Ring Systems ◽  
Space Group ◽  
Benzylic Carbon ◽  
Central Bond

[2.4]Paracyclophane crystallizes in the orthorhombic space group Pbca with cell constants (at —95°C) a = 1151.5(5), b = 1832.9(7), c = 1304.1(4) pm. The structure was refined to R = 0.053 for 1626 unique observed reflections. The aromatic ring systems are inclined to each other at an angle of 21°. The longer bridge is capable of more relaxation than the shorter, as is reflected in the non-bonded distances 279, 386 pm between bridgehead atoms and in the smaller displacements of the associated benzylic carbon atoms from the aromatic ring planes. The central bond length of the longer bridge (151.8 pm) is shorter than would be expected for a single bond.

Size Dependent Bond Length of Metallic Clusters by Considering Bond Number

2016 ◽  
Vol 850 ◽  
pp. 314-318
Author(s):  
Hui Li ◽  
Hao Jie Xiao ◽  
Jiang Wang ◽  
Hai Xia Zhang ◽  
Hai Cheng Xuan ◽  
...  
Keyword(s):  
Bond Length ◽  
Bond Number ◽  
Single Bond ◽  
Metallic Clusters ◽  
Structure Relaxation ◽  
Atomic Structures ◽  
Size Dependent ◽  
Model Free ◽  
Theoretical Predictions ◽  
Ag Clusters

In this study, size-dependent bond length of metallic clusters is established by introducing bond number. This model, free of any adjustable parameters, can be utilized to predict the change rule of bond length with size. If the atomic structure of a cluster is known, the size and shape-dependent bond number are obtained. The cubooctahedral structure is taken for simplicity to describe the shape and geometric characteristics of metallic clusters. It is found that the bond length decreases with the decreased size of metallic clusters, which is due to the structure relaxation and enhanced single bond energy. The theoretical predictions are consistent with the evidences of the simulations for Au and Ag clusters. This confirms the validity of taking cubooctahedron structure, even if the simulated Au and Ag clusters are not cuboctahedron ones. This can be expected to other metallic clusters even with other atomic structures.

scholarly journals Crystal structure of (1-ethoxyethylidene)dimethylazanium tetraphenylborate

2015 ◽  
Vol 71 (12) ◽  
pp. o984-o985
Author(s):  
Ioannis Tiritiris ◽  
Stefan Saur ◽  
Willi Kantlehner
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Bond Length ◽  
Single Bond ◽  
Charge Delocalization ◽  
Double Bond Character ◽  
Iminium Ions ◽  
Iminium Ion ◽  
Phenyl Rings ◽  
Bond Character

In the cation of the title salt, C6H14NO+·C24H20B−, the C—N bond lengths are 1.297 (2), 1.464 (2) and 1.468 (2) Å, indicating double- and single-bond character, respectively. The C—O bond length of 1.309 (2) Å shows double-bond character, pointing towards charge delocalization within the NCO plane of the iminium ion. In the crystal, C—H...π interactions between the iminium H atoms and the phenyl C atoms of the anion are present. The phenyl rings form aromatic pockets, in which the iminium ions are embedded.

scholarly journals N,N,N′,N′,N′′,N′′,N′′′,N′′′-Octamethyl(but-2-yne)bisamidinium bis(tetraphenylborate)

IUCrData ◽  
2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Ioannis Tiritiris ◽  
Ralf Kress ◽  
Willi Kantlehner
Keyword(s):  
Double Bond ◽  
Bond Length ◽  
Triple Bond ◽  
Carbon Chain ◽  
Methyl Groups ◽  
Two Dimensional ◽  
Single Bond ◽  
Asymmetric Unit ◽  
Phenyl Rings ◽  
Bond Character

The asymmetric unit of the title salt, C12H24N42+.2C24H20B−, comprises half a cation and one tetraphenylborate ion. An inversion centre is situated at the mid-point of the triple C[triple-bond]C bond in the cation. The bisamidinium C—N bonds [1.3249 (11) and 1.3267 (11) Å] have double-bond character and both positive charges are delocalized between the dimethylamino groups. The bonds between the N atoms and the terminal C-methyl groups all have values characteristic for a typical single bond [1.4656 (12)–1.4687 (12) Å]. The acetylenic bond length [1.1889 (18) Å] is consistent with a triple C[triple-bond]C bond and the butyne carbon chain is almost linear. C—H...π interactions between the bisamidinium methyl H atoms and the phenyl C atoms of the tetraphenylborate ions are present. The phenyl rings form aromatic pockets, in which the cations are embedded. This leads to the formation of a two-dimensional supramolecular pattern in theabplane.

Monomeres [(Me3Si)2CH]2Al-Te-Al[CH(SiMe3)2]2 mit gewinkelter Al-Te-Al-Gruppe / Monomeric [(Me3Si)2CH]2Al-Te-Al[CH(SiMe3)2] 2 with a Bent Al-Te-Al Group

1994 ◽  
Vol 49 (7) ◽  
pp. 931-934 ◽  
Author(s):  
Werner Uhl ◽  
Uwe Schütz
Keyword(s):  
Solid State ◽  
Bond Length ◽  
Title Compound ◽  
Single Bond ◽  
Hindered Rotation ◽  
Coordination Numbers ◽  
Mild Conditions ◽  
High Yields

AbstractTetrakis[bis(trimethylsilyl)methyl]dialane(4) 1 with an Al-Al bond and Et3P+-Te- give under mild conditions the title compound R2Al-Te-AlR2 (R = CH(SiMe3)2) 2 in high yields. Due to the high steric shielding 2 is monomeric even in the solid state with an angled Al-Te-Al group (110.4°) and an Al-Te bond length of 254.9 pm as expected for a Al-T e single bond with the atoms in low coordination numbers. A hindered rotation of the bulky substituents is observed in solution probably caused by steric restrictions similar that in ana­logous compounds with Al-S-Al or Al-CH2-Al groups.

The duodecet rule: Part 3. Fluoro species of the third period elements

1992 ◽  
Vol 70 (6) ◽  
pp. 1696-1705 ◽  
Author(s):  
E. A. Robinson
Keyword(s):  
Bond Length ◽  
Molecular Species ◽  
Central Atom ◽  
Covalent Radius ◽  
Valence Shell ◽  
Single Bond ◽  
Electron Pairs ◽  
Bond Lengths ◽  
The Third

On the basis of the suggested new value of 54 pm for the single bond covalent radius of fluorine, the previously established duodecetrule for period 3 elements in molecular species with highly electronegative ligands is extended to fluorides. It is shown, for species such as SiF4, (F3Si)2O, F3SiNH2, F3PO, and PF5, that the observed bond lengths are consistent with significant partial double bonding involving all the ligands, including fluorine, and with a total of six electron pairs in the valence shell of the central atom. Empirical rules based on d/d1, the ratio of an observed bond length to the corresponding single bond length calculated from the sum of covalent radii, are developed as a simple approximate guide to the extent of partial double bonding in bonds to third period elements. It is also shown that bond lengths in species such as Al2F5, AlO45−, and Al(NH2)4− are consistent with a duodecet rule.

The equilibrium carbon–carbon single‐bond length in ethane

1990 ◽  
Vol 93 (10) ◽  
pp. 7522-7523 ◽  
Author(s):  
Marlin D. Harmony
Keyword(s):  
Bond Length ◽  
Single Bond

scholarly journals Crystal structure of 2-bromo-3-dimethylamino-N,N,N′,N′,4-pentamethyl-4-(trimethylsilyloxy)pent-2-eneamidinium bromide

2015 ◽  
Vol 71 (12) ◽  
pp. o1061-o1062
Author(s):  
Ioannis Tiritiris ◽  
Ralf Kress ◽  
Willi Kantlehner
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Bond Length ◽  
Single Bond ◽  
Charge Delocalization ◽  
Double Bond Character ◽  
Bond Lengths ◽  
Bromide Ions ◽  
Bond Character

The reaction of the orthoamide 1,1,1-tris(dimethylamino)-4-methyl-4-(trimethylsilyloxy)pent-2-yne with bromine in benzene, yields the title salt, C15H33BrN3OSi+·Br−. The C—N bond lengths in the amidinium unit are 1.319 (6) and 1.333 (6) Å, indicating double-bond character, pointing towards charge delocalization within the NCN plane. The C—Br bond length of 1.926 (5) Å is characteristic for a C—Br single bond. Additionally, there is a bromine–bromine interaction [3.229 (3) Å] present involving the anion and cation. In the crystal, weak C—H...Br interactions between the methyl H atoms of the cation and the bromide ions are present.

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