Tag: M.W=250-300

Lindberg, James G. published the artcileQuantitative estimation of steric effects. III. Substituent constants and steric contributions to chemical shifts of methyl group protons in ring iodinated methylbenzenes, Computed Properties of 2100-25-6, the main research area is methyliodobenzene NMR substituent constant; steric effect methyliodobenzene NMR; iodomethylbenzene steric effect NMR.

PMR spectra were systematically analyzed for 27 methylbenzenes and corresponding ring iodinated derivatives based on toluene, o-, m-, and p-xylenes, mesitylene, durene, pentamethylbenzene, and hexamethylbenzene. Typical changes in the chemical shift of methyl group protons attributable to the presence of ortho, meta, and para iodine atoms and methyl groups were calculated. Unusually large low field shifts occurred in sterically crowded molecules. In ring periodinated compounds, PMR signals of methyl group protons occurred at lower fields up to 0.94 ppm relative to a predicted position, one of the largest steric shifts yet reported. A table is presented summarizing the generally useful substituent constant data obtained from examination of 59 methylbenzenes and ring halogenated derivatives

Journal of Magnetic Resonance (1969-1992) published new progress about Steric effects. 2100-25-6 belongs to class iodides-buliding-blocks, name is 3-Iodo-1,2,4,5-tetramethylbenzene, and the molecular formula is C10H13I, Computed Properties of 2100-25-6.

Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com

Galli, Carlo published the artcileStudies of substrate selectivity in aromatic iodination and other substitution reactions reinforce previous conclusions about the nature of the mechanism of electrophilic aromatic substitutions, Application of 3-Iodo-1,2,4,5-tetramethylbenzene, the main research area is substitution electrophilic aromatic mechanism substrate selectivity; iodination aromatic mechanism substrate selectivity; bromination aromatic mechanism substrate selectivity; acetylation aromatic mechanism substrate selectivity; mercuration aromatic mechanism substrate selectivity; thallation aromatic mechanism substrate selectivity; nitration aromatic mechanism substrate selectivity.

The authors have investigated substrate selectivity as a probe to distinguish between electron-transfer (ET) and conventional polar mechanisms of electrophilic aromatic substitution. Selectivity toward mesitylene and durene, in competition experiments, has been determined for iodination, bromination, acetylation, mercuration and thallation reactions under the same exptl. conditions. In all cases mesitylene, i.e., the substrate with the higher σ-basicity, was more reactive than durene; a similar behavior was shared by two other pairs of substrates, namely, mesitylene/naphthalene and m-C6H4(OMe)2/p-C6H4(OMe)2, where again the more reactive substrate within each pair was that with the higher σ-basicity. These findings suggest that the structure of the transition state of the above reactions resembles that of the σ-complex, and would therefore endorse the conventional polar mechanism of electrophilic aromatic substitution. Only for the nitration reactions were the exptl. results too ambiguous to allow a definite mechanistic conclusion to be reached.

Journal of the Chemical Society, Perkin Transactions 7: Physical Organic Chemistry published new progress about Acetoxylation. 2100-25-6 belongs to class iodides-buliding-blocks, name is 3-Iodo-1,2,4,5-tetramethylbenzene, and the molecular formula is C10H13I, Application of 3-Iodo-1,2,4,5-tetramethylbenzene.

Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com

Tietze, Lutz F. published the artcileStereoselective synthesis of steroids with the Heck reaction, Product Details of C10H13I, the main research area is double Heck reaction stereoselective steroid preparation.

The authors describe a new strategy, based on the synthesis of the B-ring of the steroid structure, via a double Heck reaction between (Z)-2-(2-bromoethenyl)bromobenzene and a hexahydro-1H-indene derivative This novel Pd-catalyzed annelation provides a general and efficient access to steroidal systems.

Angewandte Chemie, International Edition in English published new progress about Heck reaction. 2100-25-6 belongs to class iodides-buliding-blocks, name is 3-Iodo-1,2,4,5-tetramethylbenzene, and the molecular formula is C10H13I, Product Details of C10H13I.

Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com

Bekarek, V. published the artcileCorrelations between proton chemical shifts of hydroxyl groups with intramolecular hydrogen bondings and Hammett substituent constants, Quality Control of 21784-73-6, the main research area is hydrogen bonding intramol; proton chem shift; chem shift proton; shift chem proton; intramol H bonding; hydroxyl group chem shift; Hammett substituent constant.

The dependence of the proton chem. shifts of OH groups on Hammett σ constant is proposed in the form: τ = a + bσ1 + cσ2. bσ1 describes the substituent effect on the proton chem. shift of the OH group across the O-H bond and cσ2 the effect of substituents upon the electron donor involved in the formation of the H bonding. Three series of compounds were used to test the validity of the equation proposed, namely, 0-nitrophenols, salicylaldehydes, and 0-hydroxyazobenzenes. The values of the constant a, b, and c were calculated by the least sqs. method: 0-nitrophenols: -0.57, -1.260, +0.990; salicylaldehydes: -0.93, -1.186, +0.900; and 0-hydroxyazobenzenes: -1.21, -2.040, +2.484. A good agreement was found for substituted 0-nitrophenols. In the case of salicylaldehydes a considerable deviation was found for the 5-NO2 derivative There is an intramol. H bonding under exptl. conditions and such H bonding exists even in 0-hydroxyazobenzene for the data measured in Me2SO.

Collection of Czechoslovak Chemical Communications published new progress about Hydrogen bond. 21784-73-6 belongs to class iodides-buliding-blocks, name is 4-Iodo-2-nitrophenol, and the molecular formula is C6H4INO3, Quality Control of 21784-73-6.

Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com

Jones, Ian M. published the artcileRedox-dependent conformational switching of diphenylacetylenes, COA of Formula: C6H5IN2O2, the main research area is benzamido diphenylacetylene ferrocene conformation hydrogen bond mol switch.

Herein we describe the design and synthesis of a redox-dependent single-mol. switch. Appending a ferrocene unit to a diphenylacetylene scaffold gives a redox-sensitive handle, which undergoes reversible one-electron oxidation, as demonstrated by cyclic voltammetry anal. 1H-NMR spectroscopy of the partially oxidized switch and control compounds suggests that oxidation to the ferrocenium cation induces a change in hydrogen bonding interactions that results in a conformational switch.

Molecules published new progress about Conformation. 105752-04-3 belongs to class iodides-buliding-blocks, name is 4-Iodo-3-nitroaniline, and the molecular formula is C6H5IN2O2, COA of Formula: C6H5IN2O2.

Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com

Knipe, Peter C. published the artcileRemote conformational control of a molecular switch via methylation and deprotonation, Recommanded Product: 4-Iodo-3-nitroaniline, the main research area is arylcarboxamido benzamido phenylethynylbenzoate preparation conformation hydrogen bonding; dependence conformation arylcarboxamido benzamido phenylethynylbenzoate methylation deprotonation; mol crystal structure arylcarboxamido benzamido phenylethynylbenzoate.

(Arylcarboxamido)(benzamido)phenylethynylbenzoates I (R = H, Me; R1 = H, Me) were prepared and the changes in their conformations due to changes in the chemoselectivity of intramol. hydrogen bonding (whether the ester moiety accepts a hydrogen bond from the unsubstituted or substituted benzamide) were determined relative to compounds in which the benzamides cannot hydrogen bond or in which they are fully hydrogen-bonded. Removal of the Me groups led to increasing hydrogen bonding between the substituted benzamide and the ester moieties. Addition of base to I (R = H; R = Me) yielded a salt in which only the unsubstituted benzamide hydrogen bonded to the ester moiety because of the formation of a stronger hydrogen bond between the phenolate and the substituted benzamide. The structures of I (R = H, Me; R1 = Me) and of the tetrabutylammonium salt of monodeprotonated I (R = H; R1 = Me) were determined by X-ray crystallog., while the structure of the anion of monodeprotonated I (R = H; R1 = Me) was determined by calculation

Organic & Biomolecular Chemistry published new progress about Conformation. 105752-04-3 belongs to class iodides-buliding-blocks, name is 4-Iodo-3-nitroaniline, and the molecular formula is C6H5IN2O2, Recommanded Product: 4-Iodo-3-nitroaniline.

Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com

Oshikawa, Yuji published the artcileCell Surface-Anchored Fluorescent Probe Capable of Real-Time Imaging of Single Mast Cell Degranulation Based on Histamine-Induced Coordination Displacement, COA of Formula: C6H4INO3, the main research area is cell surface fluorescence probe imaging mast degranulation histamine coordination.

Mast cells secrete histamine upon degranulation triggered by various stimuli. Herein, we report the new detection method of mast cell degranulation using the fluorescent probe capable of detection of the released histamine. The probe was designed as the Co(II) complex of a cyanine dye, which shows a turn-on fluorescence signal based on a histamine-induced coordination displacement mechanism. Fluorescence imaging using the cell surface-anchored fluorescent probe enabled the real-time detection of mast cell degranulation induced by various secretagogues.

Analytical Chemistry (Washington, DC, United States) published new progress about Fluorescence. 21784-73-6 belongs to class iodides-buliding-blocks, name is 4-Iodo-2-nitrophenol, and the molecular formula is C6H4INO3, COA of Formula: C6H4INO3.

Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com

Bovonsombat, Pakorn published the artcileRing halogenations of polyalkylbenzenes with N-halosuccinimide and acidic catalysts, Computed Properties of 2100-25-6, the main research area is ring halogenation polyalkylbenzene; benzene halo; pyrrolidinedione halo halogenation polyalkylbenzene.

1-Bromo-2,5-pyrrolidinedione (NBS) and 1-chloro-2,5-pyrrolidinedione (NCS) with catalytic quantities of p-toluenesulfonic acid have been used for ring halogenations of polyalkylbenzenes. [Hydroxy(tosyloxy)iodo]benzene was effective as a catalyst with NBS but not NCS. Competition experiments with 1-iodo-2,5-pyrrolidinedione (NIS) were run to indicate selectivities in substrates, halogen sources and catalysts. With this information a mixed halogenated compound, 2-bromo-4-iodo-1,3,5-trimethylbenzene was prepared in high yield.

Synthesis published new progress about Halogenation. 2100-25-6 belongs to class iodides-buliding-blocks, name is 3-Iodo-1,2,4,5-tetramethylbenzene, and the molecular formula is C10H13I, Computed Properties of 2100-25-6.

Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com

Fabry, Jan published the artcileHigh- and low-temperature phases in isostructural 4-chloro-3-nitroaniline and 4-iodo-3-nitroaniline, Formula: C6H5IN2O2, the main research area is chloronitroaniline iodonitroaniline temperature isostructure phase; 4-chloro-3-nitroaniline; 4-iodo-3-nitroaniline; Raman; crystal structure; geometric constraints; phase transitions.

The structures of 4-chloro-3-nitroaniline, C6H5ClN2O2, (I), and 4-iodo-3-nitroaniline, C6H5IN2O2, (II), are isomorphs and both undergo continuous (second order) phase transitions at 237 and 200 K, resp. The structures, as well as their phase transitions, have been studied by single-crystal X-ray diffraction, Raman spectroscopy and difference scanning calorimetry experiments Both high-temperature phases (293 K) show disorder of the nitro substituents, which are inclined towards the benzene-ring planes at two different orientations. In the low-temperature phases (120 K), both inclination angles are well maintained, while the disorder is removed. Concomitantly, the b axis doubles with respect to the room-temperature cell. Each of the low-temperature phases of (I) and (II) contains two pairs of independent mols., where the mols. in each pair are related by noncrystallog. inversion centers. The mols. within each pair have the same absolute value of the inclination angle. The Flack parameter of the low-temperature phases is very close to 0.5, indicating inversion twinning. This can be envisaged as stacking faults in the low-temperature phases. It seems that competition between the primary amine-nitro N-H···O hydrogen bonds which form three-centered hydrogen bonds is the reason for the disorder of the nitro groups, as well as for the phase transition in both (I) and (II). The backbones of the structures are formed by N-H···N hydrogen bonding of moderate strength which results in the graph-set motif C(3). This graph-set motif forms a zigzag chain parallel to the monoclinic b axis and is maintained in both the high- and the low-temperature structures. The primary amine groups are pyramidal, with similar geometric values in all four determinations The high-temperature phase of (II) has been described previously [Garden et al. (2004). Acta Crystalline C60, o328-o330].

Acta Crystallographica, Section C: Structural Chemistry published new progress about Crystal structure. 105752-04-3 belongs to class iodides-buliding-blocks, name is 4-Iodo-3-nitroaniline, and the molecular formula is C6H5IN2O2, Formula: C6H5IN2O2.

Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com

Garden, Simon J. published the artcileHydrogen bonding in substituted nitroanilines: hydrogen-bonded sheets in 4-iodo-3-nitroaniline, Related Products of iodides-buliding-blocks, the main research area is mol structure iodonitroaniline; crystal structure iodonitroaniline; hydrogen bonding iodonitroaniline.

In the title compound, C6H5IN2O2, the nitro group is disordered over two sets of sites, each with 0.5 occupancy, and the amino N atom is pyramidal. Crystallog. data are given. The mols. are linked into sheets by a combination of three-center N-H···(O)2 H bonds involving alternative pairs of O-atom sites and two-center N-H···N H bonds involving the pyramidal amino group.

Acta Crystallographica, Section C: Crystal Structure Communications published new progress about Crystal structure. 105752-04-3 belongs to class iodides-buliding-blocks, name is 4-Iodo-3-nitroaniline, and the molecular formula is C6H5IN2O2, Related Products of iodides-buliding-blocks.

Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com