Insight into Hydrolytic Stability and Tribological Properties of B-N Coordination Tung Oil-Based Lubricant Additive in Water

A tung oil-based boron-nitrogen coordination polymer(TWE-BN)was specially designed and synthesized as a highly efficient water-based lubricant additive,which has been beneficial to both energy conservation and conducive to environmental protection.Its hydrolysis stability and tribological properties in water were investigated.To better research the lubricating properties,and thus to understand the interaction between the surface and the lubricating additives.Herein,both experimental and theoretical computations based on density functional theory(DFT)were performed.The addition of TWE-BN reduces the water friction coefficient and wear scar diameter,and the maximum non-seizure load increased from 93 to 726 N.Moreover,the anti-corrosion ability on copper was classified as 1b level.The stainless-steel surface was analyzed using scanning electron microscopy(SEM)and X-ray photoelectron spectroscopy(XPS).In hydrolytic stability testing,TWE-BN was better than nitrogen-free tung oil-based lubricant additive(TWE-B)and remained non-hydrolyzed for at least 15 days,implying the feasibility of tung oil-based boron-nitrogen coordination as highly effective and hydrolytic stability lubricant additives.

Syntheses and Crystal Structures of Two 3D Zinc(II) Compounds Involving Coordination and Hydrogen Bonds

Two zinc（Ⅱ） compounds, [Zn（L）（H2O）2]n 1 and [Zn（4,4＇-bpy）（H2O）4]（L） 2 （H2L = trans,trans-1,3 butadiene 1,4-dicarboxylic acid）, were synthesized by hydrothermal methods and characterized by single-crystal X-ray diffraction analyses. Compound 1 crystallizes in monoclinic, space group C2/c with a=15.4970（16）, b = 5.4976（6）, c = 10.7113（12） A, β=96.298（6）°, C6H8O6Zn, Mr = 241.50, V = 907.06（17） A^3, Z = 4, D, = 1.768 g/cm^3, F（000） = 488,μ = 2.703 mm^-1, S = 1.060, the final R = 0.0256 and wR = 0.0660 for 968 observed reflections with Ⅰ 〉 2σ（Ⅰ）. Compound 2 crystallizes in triclinic, space group P1^- with a = 6.915（2）, b = 7.166（2）, c = 10.363（3） A, α = 73.250（4）, β = 84.429（4）, γ = 61.605（3）°, C16H2ON2O8Zn, Mr = 433.70, V = 432.1 （2） A^3, Z = 1, D, = 1.667 g/cm^3, F（000） = 224 and μ= 1.471 mm^-1, S = 1.118, the final R = 0.0486 and wR = 0.1077 for 1352 observed reflections with Ⅰ〉 2σ（Ⅰ）. Upon using the assembly strategy of combination of coordination polymer chains with intermolecular hydrogen bonds, three-dimensional frameworks of complexes 1 and 2 were formed.

STUDY ON THE CARDANOL-ALDEHYDE CONDENSATION POLYMER CONTAINING BORON-NITROGEN COORDINATE BOND

Cardanol-aldehyde condensation polymer containing boron-nitrogen coordinate bond (CFBN) has been synthesized and characterized by IR, XPS, HPLC and DTA-TG. Its properties were also investigated. The results show that the coating film of CFBN has excellent physico-mechanical properties, good anticorrosive properties and stable at high temperature. (Author abstract) 8 Refs.

Tuning the O–O bond formation pathways of molecular water oxidation catalysts on electrode surfaces via second coordination sphere engineering

A molecular [Ru(bda)]-type(bda = 2,2’-bipyridine-6,6’-dicarboxylate) water oxidation catalyst with 4-vinylpyridine as the axial ligand(Complex 1) was immobilized or co-immobilized with 1-(trifluoromethyl)-4-vinylbenzene(3 F) or styrene(St) blocking units on the surface of glassy carbon(GC) electrodes by electrochemical polymerization, in order to prepare the corresponding poly-1@GC, poly-1+P3 F@GC, and poly-1+PSt@GC functional electrodes. Kinetic measurements of the electrode surface reaction revealed that [Ru(bda)] triggers the O–O bond formation via(1) the radical coupling interaction between the two metallo-oxyl radicals(I2 M) in the homo-coupling polymer(poly-1), and(2) the water nucleophilic attack(WNA) pathway in poly-1+P3 F and poly-1+PSt copolymers. The comparison of the three electrodes revealed that the second coordination sphere of the water oxidation catalysts plays vital roles in stabilizing their reaction intermediates, tuning the O–O bond formation pathways and improving the water oxidation reaction kinetics without changing the first coordination structures.

Structure and Fluorescence Property of a 2D Bilayer Cd(Ⅱ) Coordination Polymer Induced by H-bonding and π-π Interaction

Solvothermal reactions of 4,4＇-oxybis（benzoic acid） （H2oba） with 1,3-dipyridyl benzene （1,3-dpb） produced a two-dimensional （2D） cadmium（Ⅱ） coordination polymer {[Cd（oba）（dpb）]·H2O}n （1）. The complex was characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group C2/c with a = 13.6692（9）, b = 25.9647（17）, c = 8.7912（6） , α = 125.0370（10）, γ = 2544.7（3）°, V = 2544.7（3） 3, C30H22N2O6Cd, Mr = 618.91, Dc =1.609 g/cm3, F（000） = 1248, μ = 0.904 mm-1 and Z = 4. The neighboring Cd（Ⅱ） ions are linked by oba2-anions and 1,3-dpb to form an infinitely 2D wavelike sheet, and two such 2D sheets are interlocked with each other by H-bonding to form a 2D → 2D structure. The adjacent two groups of interlocked structures are further linked to form a bilayer 2D supramolecular network by π-π interactions. In addition, the fluorescence property of 1 was also studied.

Quasi-plane-hypothesis of strain coordination for RC beams seismically strengthened with externally-bonded or near-surface mounted fiber reinforced plastic

The application of fiber reinforced plastic（FRP）,including carbon FRP and glass FRP,for structural repair and strengthening has grown due to their numerous advantages over conventional materials such as externally bonded reinforcement（EBR） and near-surface mounted（NSM） strengthening techniques.This paper summarizes the results from 21 reinforced concrete beams strengthened with different methods,including externally-bonded and near-surface mounted FRP,to study the strain coordination of the FRP and steel rebar of the RC beam.Since there is relative slipping between the RC beam and the FRP,the strain of the FRP and steel rebar of the RC beam satisfy the quasi-plane-hypothesis;that is,the strain of the longitudinal fiber that parallels the neutral axis of the plated beam within the scope of the effective height（h 0） of the cross section is in direct proportion to the distance from the fiber to the neutral axis.The strain of the FRP and steel rebar satisfies the equation：ε FRP =βε steel,and the value of β is equal to 1.1-1.3 according to the test results.

CHARACTERIZATION AND PROPERTIES OF URUSHIOL POLYMER CONTAINING BORON-NITROGEN COORDINATE BOND

Urushiol polymer containing B-N bond (PUBN) was synthesized with urushiol-boron polymer and diethylene triamine. Its structure was characterized by XPS, IR, UV, HPLC, DTA-TG and elemental analysis. The physico-mechanical and anticorrosive properties of the polymer were also investigated. The results show that the coating of PUBN can be hardened in 2 h at room temperature and its film has excellent physico-mechanical properties and good anticorrosive properties.

Bond-Valence Sum and Distortion of Coordination Polyhedra

By using the Lagrange's intermediate value theorem,it is derived mathematically that the structur-al distortion of a coordination polyhedron may lead to an increase in bond-valence sum of the cen-tral atom of ion .The applicabilities of the bond-valence model are discussed in the following two cases:the modeling of crystal structure ,and the indication of distortion degree of a coordination polyhedron.Also it is shown that a distorted polyhedron should be in favor of a longer average bond length or a smaller coordination number.

A Self-Healing Elastomer with Extremely High Toughness Achieved by Acylsemicarbazide Hydrogen Bonding and Cu^(2+)-Neocuproine Coordination Interactions

Elastomers with high mechanical toughness can guarantee their durability during service life.Self-healing ability,as well as recyclability,can also extend the life of materials and save the consuming cost of the materials.Many efforts have been dedicated to promoting the mechanical toughness as well as the self-healing capability of elastomers at the same time,while it remains a challenge to balance the trade-off between the above properties in one system.Herein we proposed a molecular design driven by dual interactions of acylsemicarbazide hydrogen bonding and Cu^(2+)-neocuproine coordination simultaneously.By introducing the reversible multiple hydrogen bonds and strong coordination bonds,we successfully fabricated an extremely tough and self-healing elastomer.The elastomer can achieve an impressive top-notch toughness of 491 MJ/m^(3).Furthermore,it boasted rapid elastic restorability within 10 min and outstanding crack tolerance with high fracture energy(152.6kJ/m^(2)).Benefiting from the combination of dynamic interactions,the material was able to self-repair under 80℃conveniently and could be reprocessed to restore the exceptional mechanical properties.

A recyclable polyurethane with characteristic thermal stiffening behavior via B-N coordination with reversible B-O bonds

Thermal softening is an inevitable process in the physical network.Polyurethane(PU),a typical commercial material,is constructed by physical networks,which undergoes the serious thermal decay on mechanical properties at high temperature.Herein,a physically cross-linked PU with a unique thermal stiffening behavior has been developed by incorporating B–N coordination with reversible B–O bonds.The B–N coordination can significantly improve the mechanical properties of the PU.The reversible B–O bonds(temperature dependent reversible transformation between B–OH and B–O–B)are conducive to constructing more multicoordination macromolecular crosslinking points and more stable B–N coordination bonds at high temperature,endowing the PU with the special thermal stiffening behavior for the first time.Such thermal stiffening behavior compensates for the bond breakage and the network destruction caused by heat,significantly expands the rubbery plateau and delays the entire chain motion of the thermoplastic PU.As a result,the terminal flow occurs at a higher temperature up to 200°C.The modulus retention ratio of the materials is up to 87%even at 145oC,which is much higher than that of the existing PU elastomer with the physical network and even some covalent cross-link PU.Simultaneously,the physical network ensures the recyclability of the PU,and the thermal stiffening behavior is still obtained in recycled PU.This work provides a simple strategy to impart thermal stiffening behavior to the physically crosslinked PU,thereby significantly extending the operating temperature range of thermoplastic PU,which can potentially expand the scopes of PU in applications under harsh conditions.

Synthesis and Crystal Structure of a 1D Chained Coordination Polymer Containing One-dimensional Egg-like Channels:{[Cu_2(C_2O_4)_2(inta)_4](inta)}_n (inta=Isonicotinamide)

A new one-dimensional copper coordination polymer chain has been prepared and fully characterized by single-crystal X-ray diffraction, elemental analyses and IR spectroscopy. The compound { [Cu2（C2O4）2（inta）4]（inta）}n 1 crystallizes in the triclinic system, space group P1, with a = 8.4722（5）, b = 10.9825（6）, c = 11.6128（6）A, α= 104.8050（10）,β = 102.5740（10）, γ= 109.6890（10）°, V= 927.18（9） A3, Mr = 929.79, Z = 1, Dc = 1.665 g/cm^3, F（000） = 475, μ = 1.231 mm^-1, R = 0.0453 and wR = 0.1185 for 3290 observed reflections （Ⅰ 〉 2σ（Ⅰ））. Of the compound, the Cu center is octahedrally coordinated with oxalate acting as a tetra-dentate ligand coordinated to the copper atom and each inta serving as a terminal ligand by employing only one N-donor to coordinate with the Cu center. An infinite {Cu2（C2O4）2}∞ chain is formed along the c axis. Furthermore, the 1D chains are held together via extensive hydrogen-bonding interactions to generate a three-dimensional network with 1D channels （ca. 5.491A×11.507A） where inta molecules are filled.

Hydrothermal Synthesis and Crystal Structure of a Zinc(Ⅱ)Coordination Polymer Assembled by Dpphen and H_2btec/btec

A new metal-organic coordination polymer [Zn2（dpphen）2（H2btec）（btec）0.5]n （dpphen = 4,7-diphenyl- 1,10-phenanthroline, H4btec = 1,2,4, xylic acid） 1 was obtained via hydrotherrnal synthesis and characterized by elemental analysis, TG; IR spectrum and single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group P2 1/n with a = 16.2996（14）, b = 14.3332（12）, c = 25.247（2） A, β = 103.4050（10）°, V= 5737.7（9） A）, C63H37N4O12Zn2, Mr = 1172.71, Dc = 1.358 g/cm3,μ（MoKα） = 0.902 mm^-1, F（000） = 2396, Z = 4, the final R = 0.0684 and wR = 0.1281 for 3728 observed reflections （1 〉 2σ（I））. It exhibits a two-dimensional network structure constructed by mixed ligands of dpphen and H2btec/btec.

A New Co(Ⅱ) Coordination Polymer Based on a Flexible 1,4-Cyclohexanedicarboxylic Acid: Synthesis, Structure and Thermal Behavior

A new Co（Ⅱ） coordination polymer, [Co（1,4-chdc）（L）（H2O）]n（1）, was synthesized under hydrothermal condition（1,4-H2chdc = 1,4-cyclohexanedicarboxylic acid, L = 2-（4-fluoro-phenyl）-1 H-imidazo[4,5-f][1,10]phenanthroline）. Its crystal structure was determined by single-crystal X-ray diffraction. 1 crystallizes in triclinic, space group P1 with a = 8.790（5）, b = 10.486（5）, c = 13.305（5） ?, α = 87.391（5）, β = 82.925（5）, γ = 81.841（5）o, V = 1204.2（10） ?3, Z = 2, C27H23FN4O5Co, Mr = 561.42, Dc = 1.548 g/cm3, F（000） = 578, μ（Mo Ka） = 0.769 mm-1, R = 0.0415 and wR = 0.1043. In 1, each 1,4-chdc anion bridges two neighboring Co（Ⅱ） atoms to give a chain structure. The L ligands are attached on one side of the chain through chelating the Co（Ⅱ） atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a double-chain structure. The double-chain structures are linked into a supramolecular layer structure through N–H···O hydrogen-bonding interactions between the adjacent double-chain structures. Moreover, the thermal behavior of 1 was also studied.

Hydrothermal synthesis and structural studies of a new coordination polymer of lanthanum(Ⅲ) with benzene-1,2,4,5-tetracarboxylic acid and 4,4′-bipyridine

A new lanthanum complex formulated as {（bpyH2）[La（btc）（H2O）4（NO3）]·2H2O}n （1） （btcH4=benzene-1,2,4,5-tetracarboxylic acid; bpy=4,4＇-bipyridine） was hydrothermally synthesized. The complex was characterized by FT-IR spectroscopy, elemental analysis and X-ray diffraction. X-ray crystal structural analysis revealed that the compound belonged to the monoclinic space group C2/c with cell parameters a= 1.42806（7） nm, b=1.10258（5） nm, c=1.60333（8） nm and β=101.9400（10）°. The complex was polymeric with La^III atoms linked by four O atoms from two carboxylate groups of one benzene-1,2,4,5-tetracarboxylate. The LaIn atom was ten coordinated in a distorted tetracapped trigonal prism. In the crystal structure, a wide range of noncovalent interactions consisting of hydrogen bonding （of the types of O-H…O, N-H…O and C-H…O） and ion pairing interactions connected the various components into a supramolecular structure.

A Zn(Ⅱ) Coordination Polymer Based on a Flexible Symmetric Multicarboxylate Ligand

A novel coordination polymer, namely [Zn2（CAPA）（DMA）（H2O）]2n·n（H2O）（1,H4CAPA = 5-（bis（4-carboxybenzyl） amino） isophthalic acid, DMA = N,N-dimethylacetamide） has been synthesized through a solvothermal method and characterized by single-crystal X-ray diffraction, elemental analysis, infrared spectra, and thermogravimetric analyses. The crystal structure is of monoclinic, space group P21/n with a = 8.0585（5）, b = 18.9733（10）, c = 20.2044（14） A^°3, β = 101.144（7）°, V = 3030.9（3） ？~3, C56H54Zn4N4O21, Mr = 1378.58, Z = 2）. The compound forms a three-dimensional（3D） supramolecular framework by linking adjacent layers via hydrogen bonds and π···π interactions. It is interesting that the crystal structure is much related to the flexibility and configuration of the ligand. In addition, the thermal stability and luminescence properties for the compound have also been investigated.

1D Lanthanide Coordination Polymers Based on 3-(Pyridin-4-yl)benzoic Acid: Syntheses, Structures and Luminescent Properties

ABSTRACT Four novel 1D lanthanide coordination polymers with formula [Ln（3,4-pybz）3（HzO）2. H2O]n （Ln = 1 Sm; 2 Eu; 3 Tb; 4 Dy, 3,4-Hpybz = 3-（pyridin-4-yl）benzoic acid） have been synthesized by hydrothermal reactions of lanthanide oxide and 3-（pyridine-4-yl） benzoic acid. Single-crystal X-ray diffraction shows that the four compounds are isostructural. They all crystallize in a monoelinic system, space group P1^-. They have a doubly carboxylate-bridged infinite-chain structure with alternating Ln-（carboxylate）2-Ln linkages and one chelating carboxylate group on each metal center. The Ln ion also combines to two water molecules to form an eight-coordinate square antiprismatic geometry. The pyridine nitrogen atoms of the ligand do not coordinate to the metal centers but direct the formation of a 3D network through hydrogen bonding with coordinated water molecules. The photoluminescent properties of 2 and 3 have been also studied.

Syntheses and Structures of Three Novel 1-D Lanthanide-isonicotinate Coordination Polymers

Three novel lanthanide-IN coordination polymers [Ln（IN）3（H2O）2], （Ln = Sm 1, Dy 2, Eu 3; IN = isonicotinate） have been hydrothermally synthesized and characterized by FT-IR spectra, elemental analysis and TG analysis. Single-crystal X-ray diffraction shows that 1, 2 and 3 are isostructural. Crystal data for 1： monoclinic, space group C 2/c, a = 15.8384（14）, b = 14.2662 （12）, c = 9.5073（7） A, β = 97.705（4）°, V = 2128.8（3） A^3, Z = 4, Dc = 1.724 g/cm^3, F（000） = 1084 , μ = 2.806 mm^-1 and R = 0.0226; Crystal data for 2： monoclinic, space group C 2/c, a = 15.7890（3）, b = 14.1356（6）, c = 9.5152（3） A, β= 97.899（2）°, V = 2103.52（12） A^3, Z = 4, Dc = 1.784 g/cm^3, F（000） = 1100, μ = 3.601 mm^-1 and R = 0.0406; Crystal data for 3： monoclinic, space group C 2/c, a = 15.802（5）, b = 14.242（4）, c = 9.513（3） A, β = 97.695（5）°, V = 2121.8（10） A^3, Z = 4, Dc = 1.735 g/cm^3, F（000） = 1088 ,μ = 3.004 mm^-1 and R = 0.0273. In the three compounds, the Ln（Ⅲ） centers are eight-coordinated with antiprismatic geometry. The Ln（IN）3（H2O）2 unit connects mutually to form a one-dimensional double zigzag chain via isonicotinate oxygen bridging. The infinite chains are further linked by inter-chain hydrogen-bonding to form a three-dimensional supramolecular network.

Complementary method to locate atomic coordinates by combined searching method of structure-sensitive indexes based on bond valence method

Bond valence method illustrates the relation between valence and length of a particular bond type. This theory has been used to predict structure information, but the effect is very limited. In this paper, two indexes, i.e., global instability index（GII） and bond strain index（BSI）, are adopted as a judgment of a search-match program for prediction. The results show that with GII and BSI combined as judgment, the predicted atom positions are very close to real ones. The mechanism and validity of this searching program are also discussed. The GII ＆ BSI distribution contour map reveals that the predicted function is a reflection of exponential feature of bond valence formula. This combined searching method may be integrated with other structure-determination method, and may be helpful in refining and testifying light atom positions.

Diversity of supramolecular architecture of H_2salpn coordination compounds based on its flexibility

Two complexes, [ Cu （salpn） ] · NH （ CH3 ）2 （ 1 ） and [Ni （ salpn ）·H20] （ 2 ） （ H2 salpn = N, N-bis（salicylidene）-propane-1,3-diamine） were characterized by IR, element analysis and single crystal X-ray diffraction analysis. Crystal data for complex 1 ： monoclinic, P21/C, a = 1. 097 4×10^-7 cm, b=1.4806x10-7 cm, c=1.0315×10^-7 cm, β=94.43（3）°. The Cu （II） ion in complex 1 is four coordinated with distorted square planar coordination geometry. The crystal structure of com- plex 1 consists of [ Cu（salpn）] coordination complex and a guest molecule NH（ CH3 ）2 that can act as both H-bonding donor and acceptor and plays an important role in constructing supramolecular ar- chitecture. Crystal structure data for complex 2： orthorhombic, Pnma, a = 8. 676 3 ×10^-8 cm, b = 2. 414 5 ×10^-7 cm, c = 7. 538 8×10^-8 cm. The Ni（II） ion in complex 2 is five-coordinated with a but- terfly coordination geometry. The coordinated water molecule plays a key role in hydrogen-bonded networks.

Syntheses and Structures of Two New Coordination Polymers:[Cu(C_(14)H_9O_4)(C_(14)H_(10)O_4)(C_(12)H_(12)N_2)_2] and [Ag(C_(14)H_9O_4)(C_(13)H_(14)N_2)]·0.5H_2O

Under hydrothermal conditions, two new ribbon-like structures, [Cu(C14H9O4)- (C14H10O4)(C12H12N2)2] 1 and [Ag(C14H9O4)(C13H14N2)]0.5H2O 2, were obtained. X-ray crystal analysis revealed that these structures were constructed by mixed ligands. The coordination polymer forms the basic architecture while the weak interactions extend the framework into a secondary structure. The whole structures of them are governed by collaboration of the strong and weak interactions. Compound 1 crystallizes in monoclinic, space group C2/c with a = 17.0485(3), b = 11.0558(3), c = 22.7623(4) ? ?= 102.465(1), V = 4189.2(2) 3, Z = 4, Mr = 915.44, Dc = 1.451 g/mL, F(000) = 1904 and m(MoKa) = 0.587 cm-1. The final R and wR are 0.0430 and 0.1022, respectively for 3037 observed reflections with I > 2s(I). Compound 2 crystallizes in monoclinic, space group P21/c with a = 11.5963(4), b = 11.7004(5), c = 17.1254(5) ? ?= 95.620(1), V = 2312.4(1) 3, Z = 4, Mr = 556.35, Dc = 1.598 g/mL, F(000) = 1132 and m(MoKa) = 0.912 cm-1. The final R and wR are 0.0431 and 0.1050, respectively for 2629 observed reflections with I > 2σ(I).