Intermolecular interaction studies in ammonium squarate: crystal structure and vibrational spectra

Georgopoulos, Stéfanos Leite; Diniz, Renata; Rodrigues, Bernardo L.; Yoshida, María Irene; Oliveira, Luiz Fernando Cappa de

doi:10.1016/j.molstruc.2005.06.014

Cited by 30 publications

(18 citation statements)

References 26 publications

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“…The participation of the OH groups of H 2 Sq and HSq @ species in strong (2.495 and 2.587 Å ) intermolecular interactions causes a low frequency shifting of these IR-bands to 2,450 cm @1 . These data correct well with previously reported values for squaric acid derivatives, with the obtained differences being fewer than 10 cm @1 [10,11]. The observed broad absorption maximum within the whole 3,500-2,400 cm @1 IR-region is assigned to asymmetric and symmetric stretching (m as NH4+ , m s NH4+ ) vibrations of the NH 4 + anions.…”

Section: Ir-ld Spectroscopic Datasupporting

confidence: 92%

“…The optimized geometry parameters (Scheme 2) show that the bond lengths and angles in the interacted moieties are similar and differ less than 0.0300 Å and 0.02 o . The obtained geometry parameters are in accordance with those of isolated H 2 Sq and HSq @ [10,11]. Can we describe the interacting H 2 Sq/HSq @ system as consisting of separately molecules H 2 Sq an HSq @ , joined by intermolecular interactions or to a first approximation do we have the characteristics of a hydrogen bonding influenced H 2 Sq and HSq @ system?…”

Section: Theoretical Calculationssupporting

confidence: 70%

“…The observed broad absorption maximum within the whole 3,500-2,400 cm @1 IR-region is assigned to asymmetric and symmetric stretching (m as NH4+ , m s NH4+ ) vibrations of the NH 4 + anions. According to literature data, gaseous ammonia gives infrared bands at 3,414 (m 3 vibration), 3,336/3,338 (m 1 ) and 1,628 cm @1 , whereas the spectrum of solid ammonia contains corresponding bands at 3,378, 3,223 and 1,646 cm @1 [10]. The broad character of the IR-spectroscopic pattern is typical for the whole 1,850-400 cm @1 IRregion, which is typical for systems with strong hydrogen bonding interactions in the solid-state [8].…”

Section: Ir-ld Spectroscopic Datamentioning

confidence: 92%

“…3.1) is characterized by an underlying complicated IR-spectroscopic pattern like other squaric acid derivatives [7][8][9][10][11][12][13][14]. However in this case the presence of the ammonium cation and H 2 O molecules, both possessing series of stretching and bending characteristic IR-bands, leads to strong overlapping of the bands especially in the 3,500-2,800 cm @1 region.…”

Section: Ir-ld Spectroscopic Datamentioning

confidence: 99%

“…As established in series of systematic crystallographic studies on the self-assembly of squarates and hydrogensquarates [1][2][3][4][5][6]. Detailed studied on the correlation of vibrational spectroscopic properties and structural motifs in squaric acid derivatives have been reported [7][8][9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

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Crystal structure and spectroscopic properties of ammonium hydrogensquarate squaric acid monohydrate

et al. 2007

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The structure of ammonium hydrogensquarate squaric acid monohydrate has been determined by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group C2/c and exhibits a 3D network with molecules linked by intermolecular interactions with participation of the H 2 Sq, HSq @ , NH 4 + , and H 2 O species. The HSq @ anion and the neutral H 2 Sq form a strong headto-tail dimer through O-HÁÁÁO hydrogen bonding with lengths of 2.587 and 2.494 Å (protected space between numeral and unit). The layers are connected by ammonium cations and water molecules in a plane through the OÁÁÁN (2.950, 2.978, 3.036 Å ) and OÁÁÁO (2.953, 2.781 Å ) bonds. Another such layer is connected to the NH 4 + cation in the adjacent plane through bifurcated N-HÁÁÁO hydrogenbonding to form a double layer (NHÁÁÁO bond lengths are 3. 036, 2.978, 2.857, 2.909, 2.958, and 2.742 Å , respectively). The IR-band assignment of the compound was achieved using the polarized IR-spectroscopy of oriented colloids in a nematic host. Theoretical ab initio calculations were performed and achieved with a view to explain the IR-bands of the H 2 Sq.HSq @ motif.

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Section: Ir-ld Spectroscopic Datasupporting

confidence: 92%

Section: Theoretical Calculationssupporting

confidence: 70%

Section: Ir-ld Spectroscopic Datamentioning

confidence: 92%

Section: Ir-ld Spectroscopic Datamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Crystal structure and spectroscopic properties of ammonium hydrogensquarate squaric acid monohydrate

et al. 2007

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Energetics of Organomanganese Compounds

Liebman

Slayden

2011

Patai's Chemistry of Functional Groups

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Diverse aspects of the energetics of organomanganese compounds are considered in this chapter. Bond energies, enthalpies of formation and enthalpies of reaction are discussed. Classical combustion calorimetry plays only a small role compared to reaction calorimetry and techniques from contemporary ion energetics. While carbonyl, cyano, cyclopentadienyl, and benzene derivatives dominate the discussion, species with numerous other σ and/or π‐bonded ligands also appear. Quantitation is given whenever possible.

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Investigations on Squaric Acid in Superacidic Media

Schickinger

Cibu

Zischka

et al. 2018

Chemistry A European J

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The syntheses of [OC(COX) ][MF ] and [(COX) ][MF ] ⋅2 HF were carried out in superacidic media XF/MF (M=As, Sb; X=H, D). The degree of protonation is highly dependent on the stoichiometric ratio of the Lewis acid with regard to squaric acid. The salts of diprotonated squaric acid were characterized by Raman spectroscopy and, in the case of [(COH) ][MF ] ⋅2 HF (M=As, Sb), by single-crystal X-ray structure analyses. [(COH) ][AsF ] crystallizes in the monoclinic space group P2 /n with two formula units per unit cell. Analysis of the vibrational spectra was achieved with the support of quantum chemical calculations of the cation [(COH) ] ⋅4 HF on the PBE1PBE/6-311G++(3df,3pd) level of theory. Furthermore, a salt of monoprotonated squaric acid, [OC(COH) ][AsF ], was characterized by a single-crystal X-ray structure analysis. It crystallizes in the monoclinic space group P2 /n with four formula units per unit cell. The protonation of squaric acid leads to a change of the carbon skeleton, which is discussed for the entire series, starting with the dianion of squaric acid and ending with the tetrahydroxy dication.

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Intermolecular interaction studies in ammonium squarate: crystal structure and vibrational spectra

Cited by 30 publications

References 26 publications

Crystal structure and spectroscopic properties of ammonium hydrogensquarate squaric acid monohydrate

Crystal structure and spectroscopic properties of ammonium hydrogensquarate squaric acid monohydrate

Energetics of Organomanganese Compounds

Investigations on Squaric Acid in Superacidic Media

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