A Study on the Crystal Transformation Relationships of Valacyclovir Hydrochloride Polymorphs: Sesquihydrate, Form I, and Form II

2021 ◽  
pp. 2100084
Author(s):  
Yan‐Fang Wu ◽  
Hao Zhang ◽  
Nai‐Xing Wang ◽  
Tian Chen ◽  
Yan Liu
Keyword(s):  
Crystal Transformation

Single crystal to single crystal transformation of spin-crossover coordination polymers from 3D frameworks to 2D layers

2021 ◽  
Vol 9 (15) ◽  
pp. 5082-5087
Author(s):  
Yu Gong ◽  
Wang-Kang Han ◽  
Hui-Shu Lu ◽  
Qing-Tao Hu ◽  
Huan Tu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Single Crystal ◽  
Coordination Polymers ◽  
Ligand Exchange ◽  
Spin Crossover ◽  
Metal Organic Frameworks ◽  
Crystal Transformation ◽  
Metal Organic

New Hofmann-type metal–organic frameworks display rare and complete ligand exchange induced single crystal to single crystal transformations from 3D frameworks to 2D layers, accompanied by magnetic properties transition from two-step SCO behavior to hysteretic SCO behavior.

scholarly journals Solid-State Conformational Flexibility at Work: Energetic Landscape of a Single Crystal-to-Single Crystal Transformation in a Cyclic Hexapeptoid

2021 ◽  
Vol 21 (2) ◽  
pp. 897-907
Author(s):  
Giovanni Pierri ◽  
Marta Corno ◽  
Eleonora Macedi ◽  
Maria Voccia ◽  
Consiglia Tedesco
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Conformational Flexibility ◽  
Crystal Transformation

scholarly journals Interfacial Compatibility on the Crystal Transformation of Isotactic Poly (1-Butene)/Herb Residue Composite

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1654
Author(s):  
Bo Wang ◽  
Shuangdan Mao ◽  
Fuhua Lin ◽  
Mi Zhang ◽  
Yuying Zhao ◽  
...  
Keyword(s):  
Beneficial Effect ◽  
Crystal Form ◽  
Spontaneous Transformation ◽  
Water Contact ◽  
Crystal Transformation ◽  
Transformation Time ◽  
Organic Functional Groups ◽  
Silane Coupling ◽  
Interfacial Compatibility ◽  
Thermal Stability Of

Isotactic poly (1-butene) (iPB) has excellent properties which are recognized as a green and energy saving product. However, the most stable and valuable crystal form I had a spontaneous transformation that took as long as seven days to complete. As a special solid waste, the herb residue (HR) is rich in cellulose which has great potential to accelerate the crystal transformation of the iPB. However, the polarity of HR results in the interface compatibility with non-polar iPB. In this study, the HR was modified by silane coupling agent (KH570) to obtain KHR and the iPB/HR composite was prepared. The FTIR spectrum was indicated that the organic functional groups of KH570 successfully graft onto the surface of HR and the water contact angle test was indicated that the hydrophilicity of the KHR was greatly decreased. The complete crystal transformation time is 7 days for iPB, 6 days for iPB+5% HR but only 3 days for iPB+5% KHR. The addition of the HR and KHR improve the thermal stability of the composite and this beneficial effect is more obvious for KHR. After annealing for 5 days, the physical properties value include tensile strength, flexural strength, and HDT of iPB+5% HR reach that of pure iPB after annealing for 7 days, but only 3 days for iPB+5% KHR. The TG analysis and SEM photographs give clear evidence that the beneficial effect of KH570 modified HR on improving the interface compatibility with iPB.

scholarly journals Crystal-to-Crystal Transformation from K2[Co(C2O4)2(H2O)2]·4H2O to K2[Co(μ-C2O4)(C2O4)]

2021 ◽  
Vol 7 (6) ◽  
pp. 77
Author(s):  
Bin Zhang ◽  
Yan Zhang ◽  
Guangcai Chang ◽  
Zheming Wang ◽  
Daoben Zhu
Keyword(s):  
Hydrogen Bond ◽  
Physical Properties ◽  
Crystal Structures ◽  
Molecular Crystal ◽  
Trigonal Prism ◽  
Space Group ◽  
Cell Parameters ◽  
Oxalate Anion ◽  
Crystal Transformation ◽  
Antiferromagnetic Ordering

Crystal-to-crystal transformation is a path to obtain crystals with different crystal structures and physical properties. K2[Co(C2O4)2(H2O)2]·4H2O (1) is obtained from K2C2O4·2H2O, CoCl2·6H2O in H2O with a yield of 60%. It is crystallized in the triclinic with space group P1 and cell parameters: a = 7.684(1) Å, b = 9.011(1) Å, c = 10.874(1) Å, α = 72.151(2)°, β = 70.278(2)°, γ = 80.430(2)°, V = 670.0(1) Å3, Z = 2 at 100 K. 1 is composed of K+, mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. Co2+ is coordinated by two bidentated oxalate anion and two H2O in an octahedron environment. There is a hydrogen bond between mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. K2[Co(μ-C2O4)(C2O4)] (2) is obtained from 1 by dehydration. The cell parameters of 2 are a = 8.460(5) Å, b = 6.906 (4) Å, c = 14.657(8) Å, β = 93.11(1)°, V = 855.0(8) Å3 at 100 K, with space group in P2/c. It is composed of K+ and zigzag [Co(μ-C2O4)(C2O42−]n chain. Co2+ is coordinated by two bisbendentate oxalate and one bidentated oxalate anion in trigonal-prism. 1 is an antiferromagnetic molecular crystal. The antiferromagnetic ordering at 8.2 K is observed in 2.

Water molecule induced reversible single-crystal-to-single-crystal transformation between two trinuclear Fe(ii) complexes with different spin crossover behaviour

2018 ◽  
Vol 47 (12) ◽  
pp. 4307-4314 ◽  
Author(s):  
Wen-Bin Chen ◽  
Yan-Cong Chen ◽  
Meng Yang ◽  
Ming-Liang Tong ◽  
Wen Dong
Keyword(s):  
Water Molecule ◽  
Single Crystal ◽  
Spin Crossover ◽  
Crystal Transformation

Water molecule induced reversible single-crystal-to-single-crystal transformation between two trinuclear Fe(ii) complexes with different spin crossover behaviour.

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