Synthesis of complementary double-stranded helical oligomers through chiral and achiral amidinium-carboxylate salt bridges and chiral amplification in their double-helix formation

A series of complementary molecular strands from 2-mer to 5-mer that are composed of m-terphenyl units bearing chiral/achiral amidine or achiral carboxyl groups linked via Pt(II) acetylide complexes were synthesized by sequential stepwise reactions, and their chiroptical properties on the double-helix formation were investigated by circular dichroism (CD) and (1)H NMR spectroscopies. In CHCl(3), the "all-chiral" amidine strands consisting of (R)- or (S)-amidine units formed preferred-handed double helices with the complementary achiral carboxylic acid strands through the amidinium-carboxylate salt bridges, resulting in characteristic induced CDs in the Pt(II) acetylide complex regions, indicating that the chiral substituents on the amidine units biased a helical sense preference. The Cotton effect patterns and intensities were highly dependent on the molecular lengths. The complementary double-helix formation was also explored using the chiral/achiral amidine strands with different sequences in which a chiral amidine unit was introduced at the center (center-chiral) or a terminus (edge-chiral) of the amidine strands. The effect of the sequences of the chiral and achiral amidine units on the amplification of chirality (the "sergeants and soldiers" effect) in the double-helix formation was investigated by comparing the CD intensities with those of the corresponding all-chiral amidine double helices with the same molecular lengths. Variable-temperature CD experiments of the all-chiral and chiral/achiral amidine duplexes demonstrated that the Pt(II)-linked complementary duplexes are dynamic and their chiroptical properties including the chirality transfer from the chiral amidine unit to the achiral amidine ones are significantly affected by the molecular lengths, sequences, and temperatures. On the basis of the above results together with molecular dynamics simulation results, key structural features of the Pt(II)-linked oligomer duplexes and the effect of the chiral/achiral amidine sequences on the amplification of chirality are discussed.     

Controllability of dynamic double helices: quantitative analysis of the inversion of a screw-sense preference upon complexation

We describe a quantitative analysis of the complexation-induced inversion of a screw-sense preference based on a conformationally dynamic double-helix structure in a macrocycle. The macrocycle is composed of two twisting units (terephthalamide), which are spaced by two strands (1,3-bis(phenylethynyl)benzene), and is designed to generate a double-helix structure through twisting about a C₂ axis in a conrotatory manner. The attachment of chiral auxiliaries to the twisting units induces a helical preference for a particular sense of (M)- or (P)-helicity through the intramolecular transmission of chirality to dynamic double helices. The twisting unit can also act as a binding site for capturing a guest molecule, and, in a complexed state, the preferred screw sense of the dynamic double-helix structure is reversed to exhibit the contrary preference. We quantitatively monitored the complexation-induced inversion of the screw-sense preference using ¹H NMR spectroscopy, which enabled us to observe independently two species with (M)- or (P)-helicity in both the absence and presence of a guest molecule. Inversion of the screw-sense preference was induced upon complexation with an achiral guest as well as a chiral guest.     

Can Serendipity Still Hold Any Surprises in the Coordination Chemistry of Mixed-Donor Macrocyclic ligands? The Case Study of Pyridine-Containing 12-Membered Macrocycles and Platinum Group Metal ions PdII,PtII, and RhIII

This study investigates the coordination chemistry of the tetradentate pyridine-containing 12-membered macrocycles L¹-L³ towards Platinum Group metal ions Pd^II, Pt^II, and Rh^III. The reactions between the chloride salts of these metal ions and the three ligands in MeCN/H₂O or MeOH/H₂O (1:1 v/v) are shown, and the isolated solid compounds are characterized, where possible, by mass spectroscopy and ¹H- and ¹³C-NMR spectroscopic measurements. Structural characterization of the 1:1 metal-to-ligand complexes [Pd(L¹)Cl]₂[Pd₂Cl₆], [Pt(L¹)Cl](BF₄), [Rh(L¹)Cl₂](PF₆), and [Rh(L³)Cl₂](BF₄)·MeCN shows the coordinated macrocyclic ligands adopting a folded conformation, and occupying four coordination sites of a distorted square-based pyramidal and octahedral coordination environment for the Pd^II/Pt^II, and Rh^III complexes, respectively. The remaining coordination site(s) are occupied by chlorido ligands. The reaction of L₃ with PtCl₂ in MeCN/H₂O gave by serendipity the complex [Pt(L³)(μ-1,3-MeCONH)PtCl(MeCN)](BF₄)₂·H₂O, in which two metal centers are bridged by an amidate ligand at a Pt1-Pt2 distance of 2.5798(3) Å and feature one square-planar and one octahedral coordination environment. Density Functional Theory (DFT) calculations, which utilize the broken symmetry approach (DFT-BS), indicate a singlet d⁸-d⁸ Pt^II-Pt^II ground-state nature for this compound, rather than the alleged d⁹-d⁷ Pt^I-Pt^III mixed-valence character reported for related dinuclear Pt-complexes.     

A Remarkable cis‐ and trans‐Spanning Dibenzylidene Acetone Diphosphine Chelating Ligand (dbaphos)

A multidentate and flexible diolefin–diphosphine ligand, based on the dibenzylidene acetone core, namely dbaphos ( 1 ), is reported herein. The ligand adopts an array of different geometries at Pt, Pd and Rh. At Pt^II the dbaphos ligand forms cis‐ and trans‐diphosphine complexes and can be defined as a wide‐angle spanning ligand. ¹H NMR spectroscopic analysis shows that the β‐hydrogen of one olefin moiety interacts with the Pt^II centre (an anagostic interaction), which is supported by DFT calculations. At Pd⁰ and Rh^I, the dbaphos ligand exhibits both olefin and phosphine interactions with the metal centres. The Pd⁰ complex of dbaphos is dinuclear, with bridging diphosphines. The complex exhibits the coordination of one olefin moiety, which is in dynamic exchange (intramolecular) with the other “free” olefin. The Pd⁰ complex of dbaphos reacts with iodobenzene to afford trans‐[Pd^II(dbaphos)I(Ph)]. In the case of Rh^I, dbaphos coordinates to form a structure in which the phosphine and olefin moieties occupy both axial and equatorial sites, which stands in contrast to a related bidentate olefin, phosphine ligand (“Lei” ligand), in which the olefins occupy the equatorial sites and phosphines the axial sites, exclusively.     

Thermodynamic and kinetic stabilities of complementary double helices utilizing amidinium-carboxylate salt bridges

A series of dimer strands consisting of m-terphenyl backbones bearing complementary chiral or achiral amidines and achiral carboxylic acid residues connected by various types of linkers, such as diacetylene, Pt(II)-acetylide, and p-diethynylbenzene linkages, were synthesized by a modular strategy, and their chiroptical properties on the complementary double helix formations were investigated by absorption, circular dichroism (CD), and (1)H NMR spectroscopies. The thermodynamic and kinetic stabilities of the complementary double helices assisted by amidinium-carboxylate salt bridges are highly dependent on their linkages, and the thermodynamic analyses of the dimer duplexes revealed that the association constants increased in the order: Pt(II)-acetylide linker < p-diethynylbenzene linker < diacetylene linker, which is in agreement with the reverse order of their bulkiness. The substituents on the amidine groups were also found to affect the stabilities on the duplexes and the association constants increased in the order: isopropyl < (R)-1-phenylethyl < cyclohexyl. In addition, the introduction of electron-donating and/or electron-withdrawing substituents at the phenyl groups of the p-diethynylbenzene linkers connecting the amidine and carboxylic acid units, respectively, tends to stabilize the complementary double helices, especially in polar solvents, such as DMSO, due to the attractive charge-transfer interactions between the aromatic linkers, although the salt bridge formation is hampered in DMSO. Furthermore, the kinetic analyses of the chain exchange reactions for the duplexes bearing diacetylene and p-diethynylbenzene linkages showed that these were slow processes with negative ΔS([symbol: see text]) values, meaning that the chain exchange reactions proceed via direct exchange pathways. In contrast, those for the duplexes bearing Pt(II)-acetylide linkages were fast processes supported by positive ΔS([symbol: see text]) values, suggesting that the chain exchange reactions proceed via dissociation-exchange ones. The helix-inversion kinetics investigated for the racemic dimer duplexes composed of achiral amidines based on variable-temperature (1)H NMR measurements indicated that the barriers for the helix-inversion increased in the order: Pt(II)-acetylide linker, p-diethynylbenzene linker < diacetylene linker.     

Spontaneous Translocation of Antitumor Oxaliplatin,its Enantiomeric Analogue,and Cisplatin from One Strand to Another in Double‐Helical DNA

Oxaliplatin and cisplatin belong to the class of platinum‐based anticancer agents. Formation of DNA adducts by these complexes and the consequences for its structure and function, is the mechanistic paradigm by which these drugs exert their antitumor activity. We show that employing short oligonucleotide duplexes containing single, site‐specific 1,3‐intrastrand cross‐links of oxaliplatin, its enantiomeric analogue, or cisplatin and by using gel electrophoresis that under physiological conditions the coordination bonds between platinum and the N7 position of guanine residues involved in the cross‐links of the Pt^II complexes can be cleaved. This cleavage may lead to linkage isomerization reactions between these metallodrugs and double‐helical DNA. For instance, approximately 25 % 1,3‐intrastrand cross‐links of the platinum complexes isomerized after 192 h (at 310 K in 200 mM NaClO₄). Differential scanning calorimetry of duplexes containing single, site‐specific cross‐links of oxaliplatin, its enantiomeric analogue, and cisplatin reveals that one of the driving forces that leads to the lability of DNA cross‐links of these metallodrugs is a difference between the thermodynamic destabilization induced by the cross‐link and by the adduct into which it could isomerize. The rearrangements may proceed in the way that cross‐links originally formed in one strand of the DNA can spontaneously translocate from one DNA strand to its complementary counterpart, which may evoke walking of the platinum complex on DNA molecule. In addition, the differences in the kinetics of the rearrangement reactions and the thermodynamic destabilization of DNA observed for adducts of oxaliplatin and its enantiomeric analogue confirm that the chirality at the carrier 1,2‐diaminocyclohexane ligand can considerably affect structural and other physical properties of DNA adducts and consequently their biological effects. In aggregate, interesting generalization of the results described in this work might be that the migration of oxaliplatin, its enantiomeric analogue, or cisplatin from one strand to another in double‐helical DNA controlled by energetic signatures of these agents might contribute to a better understanding of their cytotoxic and mutagenic potential.     

Photolysis and Thermolysis of Platinum(IV) 2,2′‐Bipyridine Complexes Lead to Identical Platinum(II)–DNA Adducts

Two Pt^IV and two Pt^II complexes containing a 2,2′‐bipyridine ligand were treated with a short DNA oligonucleotide under light irradiation at 37 °C or in the dark at 37 and 50 °C. Photolysis and thermolysis of the Pt^IV complexes led to spontaneous reduction of the Pt^IV to the corresponding Pt^II complexes and to binding of Pt^II 2,2′‐bipyridine complexes to N7 of guanine. When the reduction product was [Pt(bpy)Cl₂], formation of bis‐oligonucleotide adducts was observed, whereas [Pt(bpy)(MeNH₂)Cl]⁺ gave monoadducts, with chloride ligands substituted in both cases. Neither in the dark nor under light irradiation was the reductive elimination process of these Pt^IV complexes accompanied by oxidative DNA damage. This work raises the question of the stability of photoactivatable Pt^IV complexes toward moderate heating conditions.     

Intramolecular hydrogen‐bond‐directed coordination: trans‐bis(N‐benzoyl‐N′‐propyl­thio­urea‐κS)di­iodo­platinum(II) and trans‐bis(N‐benzoyl‐N′‐propyl­thio­urea‐κS)di­bromo­platinum(II)

In the title compounds, trans‐[PtI₂(C₁₁H₁₄N₂OS)₂], (I), and trans‐[PtBr₂(C₁₁H₁₄N₂OS)₂], (II), respectively, intramolecular N—H⋯O (propyl­amine side) hydrogen bonds in the potentially bidentate thio­urea ligands lock the carbonyl O atoms into six‐membered rings, determining the S‐mono­dentate mode of coordination of these ligands. Intramolecular N—H⋯X (X is I or Br) interactions (benzoyl­amine side) lead to slight distortions of the Pt^II coordination spheres from ideal square‐planar geometry. The Pt^II ion is located on an inversion centre in both structures.     

Solution Structure and Behavior of Benzophenone-based Achiral Bisphosphine Ligands in Noyori-Type Ru（Ⅱ）-Catalysts

We herein report on solution structural studies of Ru^Ⅱ catalysts （3a, 9） composed of achiral bisphosphine ligands （4, 8） and the enantiopure 1,2-diphenylethylenediamine （DPEN）. Complete chiral induction from enantiopure （R,R）-DPEN to achiral bisphosphine ligand 3a was observed in solution, with the complex adopting a single, stable and non-fluxional （even at 70 ℃） configuration. The coordination of the C=O moiety in 4 to the cationic Run center is considered to be of key importance in providing the higher thermodynamic and kinetic rotation barrier for the flexible bisphosphine ligand in the complex. The obtained enantioselectivity （91% enantiomeric excess） and sense of chiral induction in the hydrogenation of acetophenone were found to be solely dependent on the chirality of the 1,2-diamine. Consistent with the hydrogenation product, the （R,R）-DPEN induces a M-conformation （fight-handed） chirality for flexible phosphine ligand 4 in the complex, resulting in a 2,2-configuration about the Ru^Ⅱ center.     

New chiral 1,3-diphosphine ligands for Rh-catalyzed enantioselective hydrogenation: a search for electronic effects

New electron-rich chiral 1,3-diphosphines of the BDPP type were prepared from 1,3-diphenylpropane-1,3-diol by an economically feasible synthetic approach. The σ-donor properties of the phosphines were determined by measurement of J(³¹P–⁷⁷Se) coupling constants in the corresponding phosphine selenides. For comparison related, but electronically different, 1,3-diphosphines were considered. The new diphosphines showed good enantioselectivities as ligands in the Rh-catalyzed enantioselective hydrogenation of benchmark substrates and β-amino acid precursors (up to 98% ee). The electronic effects on the outcome of the enantioselective catalysis have been analyzed.     

Coordination Chemistry of N‐Heterocyclic Nitrenium‐Based Ligands

Comprehensive studies on the coordination properties of tridentate nitrenium‐based ligands are presented. N‐heterocyclic nitrenium ions demonstrate general and versatile binding abilities to various transition metals, as exemplified by the synthesis and characterization of Rh^I, Rh^III, Mo⁰, Ru⁰, Ru^II, Pd^II, Pt^II, Pt^IV, and Ag^I complexes based on these unusual ligands. Formation of nitrenium–metal bonds is unambiguously confirmed both in solution by selective ¹⁵N‐labeling experiments and in the solid state by X‐ray crystallography. The generality of N‐heterocyclic nitrenium as a ligand is also validated by a systematic DFT study of its affinity towards all second‐row transition and post‐transition metals (Y–Cd) in terms of the corresponding bond‐dissociation energies.     

Synthesis, structure, and biological activity of mixed-ligand platinum(II) complexes with aminonitroxides

Mixed-ligand platinum complexescis-Pt^II(R⁶NH₂)(NH₃)X₂ andcis-Pt^II(R⁵NH₂)(NH₃)X₂ (R⁶ is 2,2,6,6-tetramethyl-4-piperidyl-1-oxyl and R⁵ is 2,2,5,5-tetramethyl-3-pyrrolidinyl-1-oxyl) were synthesized by either the reaction of aminonitroxides RNH₂ with Na[Pt^II(NH₃)Cl₂I] generatedin situ (for X₂=ClI) or by replacement of the iodo-chloro ligands incis-Pt¹¹(RNH₂)(NH₃)ClI by dichloro and oxalato ligands. The complexes obtained were characterized by elemental analysis and by IR, UV, and ESR spectra. Forcis-Pt¹¹(R⁵NH₂)(NH₃)Cl₂, crystal and molecular structures were determined by X-ray diffraction analysis. Cisplatin accelerates autooxidation of methyl linoleate and the platinum nitroxide complexes synthesized exhibit antioxidant properties. The rate of isolated DNA binding with the new complexes is almost as high as that for cisplatin.cis-Pt¹¹(R⁶NH₂)(NH₃)Cl₂ exhibits the highest antitumor activity. The high antitumor activity of platinum nitroxide complexes shows that the possible “radical component” is not a crucial factor in the cytotoxic action of cisplatin. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1624–1630, September, 2000.     

Transformations of 1,3-di-p-tolyl-5-p-toluidinomethyl-1,3,5-diazaphosphorinane initiated by electrochemical oxidation at a glassy carbon electrode

Electrochemical oxidation of 1,3-di-p-tolyl-5-p-toluidinomethyl-1,3,5-diazaphosphorinane at a glassy carbon anode yields 5,5′-spirobis(1,3-di-p-tolyl-1,3,5-diazaphosphoniarinane) perchlorate and 1,3-di-p-tolyl-5-p-toluidinomethyl-1,3-diaza-2-carbenia-5-phosphorinane perchlorate. The latter reacts on a Pt^II template to give a complex of a new diphosphine ligand.     

catena‐Poly[[[μ‐1,3‐bis(diphenylphosphanyl)propane‐κ2P:P′][O‐ethyl (4‐methoxyphenyl)phosphonodithioato‐κ2S,S′]silver(I)] chloroform monosolvate]

Reaction of a mixture of AgOAc, Lawesson's reagent [2,4‐bis(4‐methoxyphenyl)‐1,3‐dithiadiphosphetane‐2,4‐disulfide] and 1,3‐bis(diphenylphosphanyl)propane (dppp) under ultrasonic treatment gave the title compound, {[Ag(C₉H₁₂O₂PS₂)(C₂₇H₂₆P₂)]·CHCl₃}_n, a novel one‐dimensional chain based on the in situ‐generated bipodal ligand [ArP(OEt)S₂]⁻ (Ar = 4‐methoxyphenyl). The compound consists of bidentate bridging 1,3‐bis(diphenylphosphanyl)propane (dppp) and in situ‐generated bidentate chelating [ArP(OEt)S₂]⁻ ligands. The dppp ligand links the [Ag{ArP(OEt)S₂}] subunit to form an achiral one‐dimensional infinite chain. These achiral chains are packed into chiral crystals by virtue of van der Waals interactions. No π–π interactions are observed in the crystal structure.     

Cobalt-catalysed asymmetric hydrovinylation of 1,3-dienes

In the presence of bidentate 1,n-bis-diphenylphosphinoalkane-CoCl₂ complexes {Cl₂Co[P ∼ P]} and Me₃Al or methylaluminoxane, acyclic (E)-1,3-dienes react with ethylene (1 atmosphere) to give excellent yields of hydrovinylation products. The regioselectivity (1,4- or 1,2-addition) and the alkene configuration (E- or Z-) of the resulting product depend on the nature of the ligand and temperature at which the reaction is carried out. Cobalt(ii)-complexes of 1,1-diphenylphosphinomethane and similar ligands with narrow bite angles give mostly 1,2-addition, retaining the E-geometry of the original diene. Complexes of most other ligands at low temperature (–40 °C) give almost exclusively a single branched product, (Z)-3-alkylhexa-1,4-diene, which arises from a 1,4-hydrovinylation reaction. A minor product is the linear adduct, a 6-alkyl-hexa-1,4-diene, also arising from a 1,4-addition of ethylene. As the temperature is increased, a higher proportion of the major branched-1,4-adduct appears as the (E)-isomer. The unexpectedly high selectivity seen in the Co-catalysed reaction as compared to the corresponding Ni-catalysed reaction can be rationalized by invoking the intermediacy of an η⁴-[(diene)[P ∼ P]CoH]⁺-complex and its subsequent reactions. The enhanced reactivity of terminal E-1,3-dienes over the corresponding Z-dienes can also be explained on the basis of the ease of formation of this η⁴-complex in the former case. The lack of reactivity of the X₂Co(dppb) (X = Cl, Br) complexes in the presence of Zn/ZnI₂ makes the Me₃Al-mediated reaction different from the previously reported hydroalkenylation of dienes. Electron-rich phospholanes, bis-oxazolines and N-heterocyclic carbenes appear to be poor ligands for the Co(ii)-catalysed hydrovinylation of 1,3-dienes. An extensive survey of chiral ligands reveals that complexes of DIOP, BDPP and Josiphos ligands are quite effective for these reactions even at –45 °C and enantioselectivities in the range of 90–99% ee can be realized for a variety of 1,3-dienes. Cobalt(ii)-complex of an electron-deficient Josiphos ligand is especially active, requiring only <1 mol% catalyst to effect the reactions.     

The synthesis of chiral amino diol tridentate ligands and their enantioselective induction during the addition of diethylzinc to aldehydes

A series of C₂-symmetric chiral amino diol tridentate ligands 3a–g were prepared from achiral bulky organolithiums, achiral bulky primary amines, and optically active epichlorohydrin (ECH). The prepared C₂-symmetric chiral amino diol tridentate ligands were capable of inducing enantioselectivity in the model reaction of aromatic and aliphatic aldehydes with diethylzinc with an ee of up to 96%. The enantioselectivity can be modulated by adjusting the steric hindrance of the achiral reagents employed in the synthesis of the chiral ligand. The configuration of the addition product depended on the configuration of the amino diol ligands, which can be simply controlled as desired by using the ECH with the desired configuration during the preparation of the ligand.     

From Symmetry Breaking to Unraveling the Origin of the Chirality of Ligated Au13Cu2 Nanoclusters

A general method, using mixed ligands (here diphosphines and thiolates) is devised to turn an achiral metal cluster, Au₁₃Cu₂, into an enantiomeric pair by breaking (lowering) the overall molecular symmetry with the ligands. Using an achiral diphosphine, a racemic [Au₁₃Cu₂(DPPP)₃(SPy)₆]⁺ was prepared which crystallizes in centrosymmetric space groups. Using chiral diphosphines, enantioselective synthesis of an optically pure, enantiomeric pair of [Au₁₃Cu₂((2r,4r)/(2s,4s)‐BDPP)₃(SPy)₆]⁺ was achieved in one pot. Their circular dichroism (CD) spectra give perfect mirror images in the range of 250–500 nm with maximum anisotropy factors of 1.2×10^?3. DFT calculations provided good correlations with the observed CD spectra of the enantiomers and, more importantly, revealed the origin of the chirality. Racemization studies show high stability (no racemization at 70 °C) of these chiral nanoclusters, which hold great promise in applications such as asymmetry catalysis.     

195Pt NMR of organoplatinum compounds

The ¹⁹⁵Pt chemical shifts of several organoplatinum compounds in solution have been determined. The δ(¹⁹⁵Pt) values of the phosphine-Pt^II and -Pt⁰ compounds lie in separate ranges, and allow the metal-diene systems to be characterized either as metallacyclopentene or as η²-bonded diene. Although the two isomers of bis(η³-allyl)Pt (VIII) formally should be regarded as Pt^II compounds their ¹⁹⁵Pt shifts clearly lie in the region for Pt⁰ compounds. The large separation between the ¹⁹⁵Pt signals and the difference in ¹⁹⁵Pt-T₁ values for the two isomers of VIII are in accord with their having different geometries around the metal.     

Flat vs. Folded Chelate Rings in cis‐PtIIa2 (a = NH3, a2 = en,a2 = 2, 2′‐bpy) Complexes of Twofold Substituted Diazine Ligands

Acid‐base and ligating properties of three bis(substituted)pyrazine (pz) and pyrimidine (pym) ligands (pyrazine‐2, 5‐dicarboxylic acid, 2, 5‐pzdcH2, 2, 3‐bis(pyridine‐2‐yl)pyrazine, 2, 3‐bppz, pyrimidine‐4, 6‐dicarboxylic acid, 4, 6‐pmdcH₂) toward cis‐Pt^IIa₂ (a = NH₃, a₂ = en, a₂ = 2, 2′‐bpy) have been studied. Combinations of pz‐N/pym‐N with donor atoms of the substituents lead to 5‐membered platinum chelates, but exclusive N, N‐coordination through the pyridyl substituents of 2, 3‐bppz can lead to a 7‐membered platinum chelate with a characteristic L‐shape of the resulting cation. It is observed for Pt^II(2, 2′‐bpy), yet not for Pt^II(en), and is a consequence of differences in sterical interactions between the 2, 3‐bppz ligand and the coligands of Pt^II.     

Formation of Metal‐Assisted Stable Double Helices in Dimers of Cyclic Bis‐Tetrapyrroles that Exhibit Spring‐Like Motion

Bidipyrrin‐bridged macrocycles, prepared from Ni^II‐bridged dipyrrin‐based nanorings by intramolecular oxidative biaryl coupling reactions, yielded [2+4]‐type Zn^II‐assisted stable twisted‐ring dimers comprising two double helices. These [2+4]‐type metal complexes can be optically resolved by chiral HPLC and exhibit tunable electronic and optical properties as a result of spring‐like motions. The double helices behave as glue to connect two macrocycles and as the screws of hinges to form thermally responsive synchronized spring systems.