Yang Kim - Academia.edu (original) (raw)
Papers by Yang Kim
Inorganic …, 1995
Research Centre for Advanced Minerals and Materials Processing, Department of Chemistry, Universi... more Research Centre for Advanced Minerals and Materials Processing, Department of Chemistry, University of Western Australia, Nedlands, WA 6009, Australia, and Institut de Chimie Min6rale et Analytique, UniversitC de Lausanne, Place du Chateau 3, CH 1005, ...
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2015
ABSTRACT Reaction of vanadyl sulfate in aqueous ethanol in the presence of sodium acetate (as bas... more ABSTRACT Reaction of vanadyl sulfate in aqueous ethanol in the presence of sodium acetate (as base) with the 1,3-aryl-linked bis-β-diketone H2 L 1 resulted in two dinuclear isomeric complexes of type cis- and trans-[(VO)2 L 2 1 ]·0.5H2O that differ in the respective orientations of the oxo groups with respect to the main coordination plane in each complex. Hierarchical adduct formation by each isomer was investigated employing pyridine (py), 4,4′-bipyridine (bpy) and pyrazine (pyz) as co-ligands. Recrystallisation of either cis- or trans-[(VO)2(L 1 )2] from pyridine resulted in each case in the corresponding cis bis-pyridine adduct in which both pyridine ligands are coordinated on the same side of the V2 L 2 plane, with the vanadium(IV) centres achieving six-coordination. In contrast, when 4,4′-bipyridine in chloroform was reacted with both isomers and the solutions allowed to evaporate slowly, then a one-dimensional zigzag coordination polymer of type {trans-[(VO)2(L 1 )2(bpy)]·8CHCl3} n was isolated in each case. Each metal centre is again six-coordinate with the oxo groups oriented trans with respect to the mean V2 L 2 plane (with the bound pyridyl groups also positioned trans). In parallel experiments when diethyl ether vapour was allowed to diffuse into the respective chloroform solutions then a different, but structurally related, stepped polymer, {trans-[(VO)2(L 1)2(bpy)]·2CHCl3} n , was isolated. Reaction of either cis- or trans-[(VO)2(L 1 )2] with pyrazine followed by slow evaporation produced the same product, identified as {cis-[(VO)2(L 1 )2(pyz)]}2·4CHCl3·MeCN. In this case two planar dinuclear metallocyclic units are bridged by two pyrazine ligands such that the overall structure is a discrete tetranuclear species.
Journal of the Chemical Society, Dalton Transactions, 1995
ABSTRACT The nature of the two principal products of the reaction between pentaerythritol [2,2-bi... more ABSTRACT The nature of the two principal products of the reaction between pentaerythritol [2,2-bis(hydroxymethyl)propane-1,3-diol] tetrabenzenesulfonate and ethane-1,2-diamine (en) has been confirmed by crystal-structure determinations on their cobalt(III) complexes, the less abundant species, 5,5-bis(4-amino-2-azabutyl)-3,7-diazanonane-1,9-diamine, L1, being characterised in its bis(quadridentate) form in a green, tetrachloro, binuclear complex, and the more abundant 6,6-bis(4-amino-2-azabutyl)-1,4-diazacycloheptane, L2, in a form where the ring nitrogen atoms are uncoordinated, as a green, mononuclear trans dichlorotetramine complex. Compounds L1 and L2 have also been characterised in various forms produced when these dichloro complexes are treated with en. In green [trans-Cl2CoL1CoCl2-trans]CI2·4H2O 1, the binuclear cation has quasi-2 symmetry about the central carbon atom of the ligand which embraces the two cobalt atoms each bound equatorially by four N atoms; Co–Cl(trans) 2.234(8)–2.251(7) and Co–N 1.92(2)–1.99(2)Å. In one isomer of the mixed-ligand complexes of L1 and en, structurally characterised both as the chloride [(en)CoL1Co(en)]Cl6·≈ 7H2O 2a, and as the nitrate [(en)CoL1Co(en)][NO3]6·6H2O 2b, the cation also has approximate 2 symmetry, broken significantly only by differing conformations of the two en ligands in 2a; Co–N 1.957(7)–1.986(4)Å. Another product of the reaction of 1 with en was the known mononuclear, orange complex [Co(H2L1)]Cl5·≈ 2.3H2O 3, where the ligand is disposed about the cobalt in a half cage, with the fourth diprotonated arm pendant from the cap; Co–N at the open end 1.977Å(mean) nearer the cap 1.964Å, the difference being significant. In green trans-[CoCl2(H2L2)]Cl3·≈ 3.45H2O 4, the bicyclic ligand co-ordinates the cobalt equatorially through four N atoms; Co–Cl(trans) 2.259(1) and 2.263(1)Å, and Co–N (pairwise) 1.946(2), 1.948(3)Å for the ‘inner’ nitrogens and 1.960(2), 1.971(2)Å for the outer/terminal nitrogens. One of the immediate products of the reaction of en with 4 was [Co(en)(H2L2)]Cl5·≈ 0.6EtOH 5. In this cation the cobalt is co-ordinated by the en and both arms of ligand L2, the seven-membered ring nitrogen atoms being unco-ordinated and protonated after isolation from acidic solution; Co–N 1.95(1)–1.986(5)Å. One of the products of more extended reaction between en and 4 was red [Co(en)(H2L2)]Cl5·3H2O 6, in which the ligand is diprotonated on the two nitrogen atoms of one of the ‘arms’; it co-ordinates through both nitrogen atoms of the seven-membered ring, cis in the co-ordination sphere [Co–N 1.986(4) and 2.012(4)Å], the two nitrogen atoms of the other ligand arm occupying a further cis pair of sites [Co–N 1.966(4) and 1.972(4)Å], with the cis pair of Co–N(en) distances being 1.975(4) and 1.981(4)Å.
Journal of the Chemical Society, Dalton Transactions, 2001
Characterisation, largely through crystal structure determinations of their metal complexes, of t... more Characterisation, largely through crystal structure determinations of their metal complexes, of the polyamine products of several reactions between (in all but one case) polyalcohol benzenesulfonates and 1,2-and 1,3-diamines, confirmed that intramolecular reaction pathways are important ...
![Research paper thumbnail of A spirobiscalix[4]azacrown: synthesis and complexing properties](https://attachments.academia-assets.com/71814607/thumbnails/1.jpg)
](Tetrahedron Letters, 2009
The synthesis and complexation properties of a novel type of calix[4]azacrown, in which two cone ... more The synthesis and complexation properties of a novel type of calix[4]azacrown, in which two cone calix[4]arenes are linked via a spiro C-atom incorporated into polyaminoalkylene chains are presented.
ChemInform, 2008
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Calixarenes in the Nanoworld, 2007
This chapter places our investigations of calixdendrimers within the context of extant literature.
Tetrahedron, 2008
Readily-synthesised, water-stable Pd(II) complexes of azetidine-based tridentate ligands have bee... more Readily-synthesised, water-stable Pd(II) complexes of azetidine-based tridentate ligands have been studied as catalysts for the Suzuki-Miyaura coupling reaction. They are highly active for the coupling of aryl bromides with aryl boronates and also effective for the coupling of aryl chlorides.
Supramolecular Chemistry, 2006
A new family of hyperbranched molecules and dendrimers has been constructed from a diamidedicali... more A new family of hyperbranched molecules and dendrimers has been constructed from a diamidedicalix derivative prepared from monocarbomethoxymethyl p-tert-butyl calix [4] arene and tris (2-aminoethyl) amine ('tren') via amide-formation reactions. The selective 1, ...
Letters in Organic Chemistry, 2006
... Mouna Mahouachi1,2, Rym Abidi1,2, Yang Kim3, Sang H. Lee4, Jong H. Jung5, Jong S. Kim6 and Ja... more ... Mouna Mahouachi1,2, Rym Abidi1,2, Yang Kim3, Sang H. Lee4, Jong H. Jung5, Jong S. Kim6 and Jacques Vicens*,1 ... s, 3H, CONH), 7.10 (broad s, 6H, ArH), 7.09 (broad s, 12H, ArH), 7.08 (broad s, 6H, ArH), 4.59 (s, 6H, ArOCH2), 4.24 (d, 6H, J = 13.7 Hz, AB system, ArCH2Ar ...
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2009
... JS Kim Á YH Lee Department of Chemistry, Korea University, Anam-dong, Seongbuk-Gu, Seoul 136-... more ... JS Kim Á YH Lee Department of Chemistry, Korea University, Anam-dong, Seongbuk-Gu, Seoul 136-701, South Korea ... CuNpy 2.05 N(1,6) 2.054(5), 2.043(5) CuN(1,10) 2.058(4) CuNaz 2.04 N(2,5) 2.043(6), 2.041(7) CuN(2,20) 2.006(5) ...
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2009
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2011
... According to the literature [7], the introduction of a pyri-dylmethyl moiety onto the seconda... more ... According to the literature [7], the introduction of a pyri-dylmethyl moiety onto the secondary nitrogen of bis(ami-nopropyl)amine causes a significant ... Kluwer Academic Publishers, Dordr-echt (2001) 5. Oueslati, I.: Calix(aza)crowns: synthesis, recognition, and coor-dination. ...
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2011
Abstract Inclusion complexes of LiClO4 or NaClO4 into [CuLSS] or [CuLrac] are reported, where [C... more Abstract Inclusion complexes of LiClO4 or NaClO4 into [CuLSS] or [CuLrac] are reported, where [CuLSS] denotes bis(3-methoxy-2-oxy-1-benzylidene)-1S,2S-cyclohexanediaminecopper(II) and [CuLrac] denotes the racemic complex. The inclusion reaction of LiClO4 and NaClO4 into [CuLSS] gave the [1 + 1] adduct of [CuLSS(H2O)LiClO4] and the [2 + 1] adduct of [(CuLSS)2Na(H2O)3]ClO4, respectively, while that of NaClO4 into [CuLrac] gave the [2 + 2] adduct of [CuLracNaClO4]2·CH3CN ([(CuLSSNaClO4)(CuLRRNaClO4)]·CH3CN). Graphical Abstract Reaction of
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2009
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2009
... JM Harrowfield Institut de Science et d'Ingénierie Supramoléculaires, Université de Stra... more ... JM Harrowfield Institut de Science et d'Ingénierie Supramoléculaires, Université de Strasbourg, 8, allée Gaspard Monge, 67083 Strasbourg, France WT Lim Department of Applied Chemistry, Andong National University, Andong, Kyungpook, South Korea ...
Inorganic Chemistry, 2004
Inorganic Chemistry Communications, 2010
European Journal of Inorganic Chemistry, 2013
ABSTRACT A quaterphenylterpyridine ligand (qptpy) with the rodlike quaterphenyl unit attached in ... more ABSTRACT A quaterphenylterpyridine ligand (qptpy) with the rodlike quaterphenyl unit attached in the 4′-position has been synthesised by a Pd-catalysed Suzuki cross-coupling reaction. A crystal structure determination on the complex [Zn(qptpy)Cl2]·dmf (dmf = dimethylformamide) has shown the ligand to be bound in the expected N3-tridentate manner to the essentially trigonal-bipyramidal dichloro metal ion, with the quaterphenyl substituents involving a twisted array of the separate phenyl groups and the shortest contacts between aromatic groups involving just the polar terpyridine head groups to give an infinite, offset face-to-face (OFF) π-stacking array. A comparison is made with the structures of the bis(ligand) complexes of Zn(ClO4)2 and Cd(ClO4)2 with the bromobiphenylterpyridine ligand (Brbptpy) synthesised as an intermediate for the formation of qptpy. A study of the absorption and emission spectra of qptpy and a range of its metal-ion complexes has shown that the ligand provides a ratiometric fluorescence response for both ZnII and CdII.
Dalton Transactions, 2013
Terpyridine ligands with ter- and quater-phenyl substituents at the 4&amp... more Terpyridine ligands with ter- and quater-phenyl substituents at the 4' position provide bis(ligand)Co(II) complexes showing very different magnetic properties to those of their analogues with long-chain aliphatic substituents, with no evidence of "re-entrant" behavior involving multiple high- and low-spin species. Structure determinations of [Co(tptpy)2](BF4)2·CH3OH and [Co(qptpy)2](BPh4)2·3.5dmf·2H2O (dmf = N,N-dimethylformamide) show the metal ion centres in both to be relatively distant and that the "terpyridine embrace" observed to be partially retained in their analogues is completely lost. Consideration of available structural and magnetic data for these and other Co(II) complexes of functionalised terpyridines and terpyridine itself provides evidence that spin crossover behaviour may be regulated by face-to-face contacts of the pyridyl units of the head groups.
Inorganic …, 1995
Research Centre for Advanced Minerals and Materials Processing, Department of Chemistry, Universi... more Research Centre for Advanced Minerals and Materials Processing, Department of Chemistry, University of Western Australia, Nedlands, WA 6009, Australia, and Institut de Chimie Min6rale et Analytique, UniversitC de Lausanne, Place du Chateau 3, CH 1005, ...
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2015
ABSTRACT Reaction of vanadyl sulfate in aqueous ethanol in the presence of sodium acetate (as bas... more ABSTRACT Reaction of vanadyl sulfate in aqueous ethanol in the presence of sodium acetate (as base) with the 1,3-aryl-linked bis-β-diketone H2 L 1 resulted in two dinuclear isomeric complexes of type cis- and trans-[(VO)2 L 2 1 ]·0.5H2O that differ in the respective orientations of the oxo groups with respect to the main coordination plane in each complex. Hierarchical adduct formation by each isomer was investigated employing pyridine (py), 4,4′-bipyridine (bpy) and pyrazine (pyz) as co-ligands. Recrystallisation of either cis- or trans-[(VO)2(L 1 )2] from pyridine resulted in each case in the corresponding cis bis-pyridine adduct in which both pyridine ligands are coordinated on the same side of the V2 L 2 plane, with the vanadium(IV) centres achieving six-coordination. In contrast, when 4,4′-bipyridine in chloroform was reacted with both isomers and the solutions allowed to evaporate slowly, then a one-dimensional zigzag coordination polymer of type {trans-[(VO)2(L 1 )2(bpy)]·8CHCl3} n was isolated in each case. Each metal centre is again six-coordinate with the oxo groups oriented trans with respect to the mean V2 L 2 plane (with the bound pyridyl groups also positioned trans). In parallel experiments when diethyl ether vapour was allowed to diffuse into the respective chloroform solutions then a different, but structurally related, stepped polymer, {trans-[(VO)2(L 1)2(bpy)]·2CHCl3} n , was isolated. Reaction of either cis- or trans-[(VO)2(L 1 )2] with pyrazine followed by slow evaporation produced the same product, identified as {cis-[(VO)2(L 1 )2(pyz)]}2·4CHCl3·MeCN. In this case two planar dinuclear metallocyclic units are bridged by two pyrazine ligands such that the overall structure is a discrete tetranuclear species.
Journal of the Chemical Society, Dalton Transactions, 1995
ABSTRACT The nature of the two principal products of the reaction between pentaerythritol [2,2-bi... more ABSTRACT The nature of the two principal products of the reaction between pentaerythritol [2,2-bis(hydroxymethyl)propane-1,3-diol] tetrabenzenesulfonate and ethane-1,2-diamine (en) has been confirmed by crystal-structure determinations on their cobalt(III) complexes, the less abundant species, 5,5-bis(4-amino-2-azabutyl)-3,7-diazanonane-1,9-diamine, L1, being characterised in its bis(quadridentate) form in a green, tetrachloro, binuclear complex, and the more abundant 6,6-bis(4-amino-2-azabutyl)-1,4-diazacycloheptane, L2, in a form where the ring nitrogen atoms are uncoordinated, as a green, mononuclear trans dichlorotetramine complex. Compounds L1 and L2 have also been characterised in various forms produced when these dichloro complexes are treated with en. In green [trans-Cl2CoL1CoCl2-trans]CI2·4H2O 1, the binuclear cation has quasi-2 symmetry about the central carbon atom of the ligand which embraces the two cobalt atoms each bound equatorially by four N atoms; Co–Cl(trans) 2.234(8)–2.251(7) and Co–N 1.92(2)–1.99(2)Å. In one isomer of the mixed-ligand complexes of L1 and en, structurally characterised both as the chloride [(en)CoL1Co(en)]Cl6·≈ 7H2O 2a, and as the nitrate [(en)CoL1Co(en)][NO3]6·6H2O 2b, the cation also has approximate 2 symmetry, broken significantly only by differing conformations of the two en ligands in 2a; Co–N 1.957(7)–1.986(4)Å. Another product of the reaction of 1 with en was the known mononuclear, orange complex [Co(H2L1)]Cl5·≈ 2.3H2O 3, where the ligand is disposed about the cobalt in a half cage, with the fourth diprotonated arm pendant from the cap; Co–N at the open end 1.977Å(mean) nearer the cap 1.964Å, the difference being significant. In green trans-[CoCl2(H2L2)]Cl3·≈ 3.45H2O 4, the bicyclic ligand co-ordinates the cobalt equatorially through four N atoms; Co–Cl(trans) 2.259(1) and 2.263(1)Å, and Co–N (pairwise) 1.946(2), 1.948(3)Å for the ‘inner’ nitrogens and 1.960(2), 1.971(2)Å for the outer/terminal nitrogens. One of the immediate products of the reaction of en with 4 was [Co(en)(H2L2)]Cl5·≈ 0.6EtOH 5. In this cation the cobalt is co-ordinated by the en and both arms of ligand L2, the seven-membered ring nitrogen atoms being unco-ordinated and protonated after isolation from acidic solution; Co–N 1.95(1)–1.986(5)Å. One of the products of more extended reaction between en and 4 was red [Co(en)(H2L2)]Cl5·3H2O 6, in which the ligand is diprotonated on the two nitrogen atoms of one of the ‘arms’; it co-ordinates through both nitrogen atoms of the seven-membered ring, cis in the co-ordination sphere [Co–N 1.986(4) and 2.012(4)Å], the two nitrogen atoms of the other ligand arm occupying a further cis pair of sites [Co–N 1.966(4) and 1.972(4)Å], with the cis pair of Co–N(en) distances being 1.975(4) and 1.981(4)Å.
Journal of the Chemical Society, Dalton Transactions, 2001
Characterisation, largely through crystal structure determinations of their metal complexes, of t... more Characterisation, largely through crystal structure determinations of their metal complexes, of the polyamine products of several reactions between (in all but one case) polyalcohol benzenesulfonates and 1,2-and 1,3-diamines, confirmed that intramolecular reaction pathways are important ...
Tetrahedron Letters, 2009
The synthesis and complexation properties of a novel type of calix[4]azacrown, in which two cone ... more The synthesis and complexation properties of a novel type of calix[4]azacrown, in which two cone calix[4]arenes are linked via a spiro C-atom incorporated into polyaminoalkylene chains are presented.
ChemInform, 2008
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Calixarenes in the Nanoworld, 2007
This chapter places our investigations of calixdendrimers within the context of extant literature.
Tetrahedron, 2008
Readily-synthesised, water-stable Pd(II) complexes of azetidine-based tridentate ligands have bee... more Readily-synthesised, water-stable Pd(II) complexes of azetidine-based tridentate ligands have been studied as catalysts for the Suzuki-Miyaura coupling reaction. They are highly active for the coupling of aryl bromides with aryl boronates and also effective for the coupling of aryl chlorides.
Supramolecular Chemistry, 2006
A new family of hyperbranched molecules and dendrimers has been constructed from a diamidedicali... more A new family of hyperbranched molecules and dendrimers has been constructed from a diamidedicalix derivative prepared from monocarbomethoxymethyl p-tert-butyl calix [4] arene and tris (2-aminoethyl) amine ('tren') via amide-formation reactions. The selective 1, ...
Letters in Organic Chemistry, 2006
... Mouna Mahouachi1,2, Rym Abidi1,2, Yang Kim3, Sang H. Lee4, Jong H. Jung5, Jong S. Kim6 and Ja... more ... Mouna Mahouachi1,2, Rym Abidi1,2, Yang Kim3, Sang H. Lee4, Jong H. Jung5, Jong S. Kim6 and Jacques Vicens*,1 ... s, 3H, CONH), 7.10 (broad s, 6H, ArH), 7.09 (broad s, 12H, ArH), 7.08 (broad s, 6H, ArH), 4.59 (s, 6H, ArOCH2), 4.24 (d, 6H, J = 13.7 Hz, AB system, ArCH2Ar ...
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2009
... JS Kim Á YH Lee Department of Chemistry, Korea University, Anam-dong, Seongbuk-Gu, Seoul 136-... more ... JS Kim Á YH Lee Department of Chemistry, Korea University, Anam-dong, Seongbuk-Gu, Seoul 136-701, South Korea ... CuNpy 2.05 N(1,6) 2.054(5), 2.043(5) CuN(1,10) 2.058(4) CuNaz 2.04 N(2,5) 2.043(6), 2.041(7) CuN(2,20) 2.006(5) ...
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2009
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2011
... According to the literature [7], the introduction of a pyri-dylmethyl moiety onto the seconda... more ... According to the literature [7], the introduction of a pyri-dylmethyl moiety onto the secondary nitrogen of bis(ami-nopropyl)amine causes a significant ... Kluwer Academic Publishers, Dordr-echt (2001) 5. Oueslati, I.: Calix(aza)crowns: synthesis, recognition, and coor-dination. ...
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2011
Abstract Inclusion complexes of LiClO4 or NaClO4 into [CuLSS] or [CuLrac] are reported, where [C... more Abstract Inclusion complexes of LiClO4 or NaClO4 into [CuLSS] or [CuLrac] are reported, where [CuLSS] denotes bis(3-methoxy-2-oxy-1-benzylidene)-1S,2S-cyclohexanediaminecopper(II) and [CuLrac] denotes the racemic complex. The inclusion reaction of LiClO4 and NaClO4 into [CuLSS] gave the [1 + 1] adduct of [CuLSS(H2O)LiClO4] and the [2 + 1] adduct of [(CuLSS)2Na(H2O)3]ClO4, respectively, while that of NaClO4 into [CuLrac] gave the [2 + 2] adduct of [CuLracNaClO4]2·CH3CN ([(CuLSSNaClO4)(CuLRRNaClO4)]·CH3CN). Graphical Abstract Reaction of
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2009
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2009
... JM Harrowfield Institut de Science et d'Ingénierie Supramoléculaires, Université de Stra... more ... JM Harrowfield Institut de Science et d'Ingénierie Supramoléculaires, Université de Strasbourg, 8, allée Gaspard Monge, 67083 Strasbourg, France WT Lim Department of Applied Chemistry, Andong National University, Andong, Kyungpook, South Korea ...
Inorganic Chemistry, 2004
Inorganic Chemistry Communications, 2010
European Journal of Inorganic Chemistry, 2013
ABSTRACT A quaterphenylterpyridine ligand (qptpy) with the rodlike quaterphenyl unit attached in ... more ABSTRACT A quaterphenylterpyridine ligand (qptpy) with the rodlike quaterphenyl unit attached in the 4′-position has been synthesised by a Pd-catalysed Suzuki cross-coupling reaction. A crystal structure determination on the complex [Zn(qptpy)Cl2]·dmf (dmf = dimethylformamide) has shown the ligand to be bound in the expected N3-tridentate manner to the essentially trigonal-bipyramidal dichloro metal ion, with the quaterphenyl substituents involving a twisted array of the separate phenyl groups and the shortest contacts between aromatic groups involving just the polar terpyridine head groups to give an infinite, offset face-to-face (OFF) π-stacking array. A comparison is made with the structures of the bis(ligand) complexes of Zn(ClO4)2 and Cd(ClO4)2 with the bromobiphenylterpyridine ligand (Brbptpy) synthesised as an intermediate for the formation of qptpy. A study of the absorption and emission spectra of qptpy and a range of its metal-ion complexes has shown that the ligand provides a ratiometric fluorescence response for both ZnII and CdII.
Dalton Transactions, 2013
Terpyridine ligands with ter- and quater-phenyl substituents at the 4&amp... more Terpyridine ligands with ter- and quater-phenyl substituents at the 4' position provide bis(ligand)Co(II) complexes showing very different magnetic properties to those of their analogues with long-chain aliphatic substituents, with no evidence of "re-entrant" behavior involving multiple high- and low-spin species. Structure determinations of [Co(tptpy)2](BF4)2·CH3OH and [Co(qptpy)2](BPh4)2·3.5dmf·2H2O (dmf = N,N-dimethylformamide) show the metal ion centres in both to be relatively distant and that the "terpyridine embrace" observed to be partially retained in their analogues is completely lost. Consideration of available structural and magnetic data for these and other Co(II) complexes of functionalised terpyridines and terpyridine itself provides evidence that spin crossover behaviour may be regulated by face-to-face contacts of the pyridyl units of the head groups.