Helical Coordination Polymers with Large Chiral Cavities

Biradha, Kumar; Seward, Corey; Zaworotko, Michael J.

doi:10.1002/(sici)1521-3773(19990215)38:4<492::aid-anie492>3.0.co;2-#

Cited by 375 publications

(34 citation statements)

References 15 publications

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“…Multicomponent systems also have been assembled by means of transition metal-based coordinate bonds (15)(16)(17)(18)(19)(20). The synthesis of hosts capable of housing a wide variety of guests has further been achieved by the use of the principles of crystal engineering (21,22). Based on this wide variety of work focused on the enclosure of chemical space, we recently put forward a set of general principles for the design of discrete spherical molecular host capsules (23)(24)(25).…”

mentioning

confidence: 99%

Organization of the interior of molecular capsules by hydrogen bonding

Atwood

Barbour

Jerga

2002

Proc. Natl. Acad. Sci. U.S.A.

211

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The enclosure of functional entities within a protective boundary is an essential feature of biological systems. On a molecular scale, free-standing capsules with an internal volume sufficiently large to house molecular species have been synthesized and studied for more than a decade. These capsules have been prepared by either covalent synthesis or self-assembly, and the internal volumes have ranged from 200 to 1,500 Å 3 . Although biological systems possess a remarkable degree of order within the protective boundaries, to date only steric constraints have been used to order the guests within molecular capsules. In this article we describe the synthesis and characterization of hexameric molecular capsules held together by hydrogen bonding. These capsules possess internal order of the guests brought about by hydrogen bond donors within, but not used by, the framework of the capsule. The basic building blocks of the hexameric capsules are tetrameric macrocycles related to resorcin[4]arenes and pyrogallol[4]arenes. The former contain four 1,3-dihydroxybenzene rings bridged together by -CHR-units, whereas the latter contain four 1,2,3-trihydroxybenzene rings bridged together. We now report the synthesis of related mixed macrocycles, and the main focus is on the macrocycle composed of three 1,2,3-trihydroxybenzene rings and one 1,3-dihydroxybenzene ring bridged together. The mixed macrocycles self-assemble from a mixture of closely related compounds to form the hexameric capsule with internally ordered guests.

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mentioning

confidence: 99%

Organization of the interior of molecular capsules by hydrogen bonding

Atwood

Barbour

Jerga

2002

Proc. Natl. Acad. Sci. U.S.A.

211

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“…The red crystals have 2D interpenetrated structure. 4 ] changed to 1D chain polymer (M(NCS) 2 (bpp)) by releasing HNCS from the cation and anion in the reaction medium. The obtained complexes were characterized by ICP-AES, ESI-MS and X-Ray-diffraction methods.…”

Section: Discussionmentioning

confidence: 99%

“…Selected bond lengths and angles are shown in Table 2. 4 ], and this is a mononuclear complex. This structure organisation explains the better dissolution of this sample in the solvent, as compared with blue and red crystals, respectively.…”

Section: X-ray Diffraction Measurementsmentioning

confidence: 99%

“…In the present study, it was shown that at the fi rst stage the ionic crystals are obtained and subsequently, the crystal changed to more stable assembled structure. 4 ]. This is not the most stable structure in the reaction vessel.…”

Section: X-ray Diffraction Measurementsmentioning

confidence: 99%

“…Up to now various assembled structures have been reported [2][3][4][5][6][7][8]. We have studied iron complexes bridged by 1,3-bis(4-pyridyl)propane (bpp), containing three methylene groups, by using single crystal X-ray diffraction analysis, Mössbauer spectroscopy and Superconducting Quantum Interference Device (SQUID) measurements.…”

Section: Introductionmentioning

confidence: 99%

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The Formation Mechanism of Assembled Complexes Bridged by 1,3–Bis(4–Pyridyl)Propane

Dote¹,

Yasuhara²,

Nakashima³

2016

ChemJMold

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Abstract. Several types of differently coloured crystals (light blue, blue and red) were obtained in the synthesis of assembled complex of mixed crystals with three metals by using solvent diffusion method. The mechanism of obtaining the assembled complexes is discussed based on the structure and colour change. The red crystal has 2D interpenetrated structure. Keywords: mixed crystal, assembled complex, 1,3-bis(4-pyridyl)propane, crystal formation. IntroductionSelf-assembled coordination polymers containing transition metal ions and organic bridging ligands have attracted intensive interest in virtue of their potential abilities for selective inclusion and transformation of ions and molecules [1]. Up to now various assembled structures have been reported [2][3][4][5][6][7][8]. We have studied iron complexes bridged by 1,3-bis(4-pyridyl)propane (bpp), containing three methylene groups, by using single crystal X-ray diffraction analysis, Mössbauer spectroscopy and Superconducting Quantum Interference Device (SQUID) measurements. Fe(NCX) 2 (bpp) 2 (X = S, Se and BH 3 ) had a 2D interpenetrated structure and the NCBH 3 complex showed a spin-crossover phenomenon [9]. When the benzene is enclathrated, the structure becomes 1D chain [10]. Recently, we discussed the spin state of the mixed crystals of iron with zinc or cobalt ion in the 2D interpenetrated structure for the assembled complexes bridged by bpp, and we revealed that NCSe complex had a lowered spin state, in comparison with pure Fe complex, because iron atom is forced to reduce its radius in the zinc or cobalt complexes having smaller unit cell [11].Herein we report on the synthesis of mixed crystals including zinc, cobalt, and iron atoms. Several types of crystals appeared and the colour changed in the reaction medium. The mechanism of obtaining the assembled complexes is put into discussion on the basis of structure and colour modifi cation.

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