Nickel 1,4-cyclohexanedicarboxylate coordination polymers – Synthesis, Characterization, Phase study, and Magnetic PropertiesPrashant Jain@, Russel K Feller#, Naresh Dalal@, Tony Cheetham#, and Harold W. Kroto@

@ Dept. of Chemistry & Biochemistry, Florida State University, # Materials Research Laboratory, University of California, Santa Barbara

Overview

Coordination polymers or metal organic frameworks are of great recent research interest due to their interesting topologies and potential applications as functional materials. Hydrothermal chemistry has been widely used for preparation of these compounds. Control of products in the hydrothermal reactions is still an exciting challenge for the chemists. Here we report the synthesis of five nickel complexes starting from identical reaction mixture. A detailed study was conducted to determine the way in which reaction conditions governed the resulting phases. Temperature and concentration were found to be the two main determining factors.

Products

Five nickel complexes were observed. Structures of three complexes were solved by single crystal XRD.

For complex 4 (space group R3-c) the temperature dependence of reciprocal of the susceptibility is linear above 60 K and obeys the Curie-Weiss law with a Weiss constant θ = -146.89 K and C = 9.43 cm3 K mol-1. The C value correspond to the six non-interacting Ni II ions (S=1) with g = 2.21. χT value at room temperature (6.33 cm3 K mol-1) is lower then an expected value (7.33 cm3 K mol-1).

Effect of reaction conditions

As shown in the reaction condition diagram, it was possible to synthesize pure complexes. Other variables (eg. solvent volume, fill volume, stirring etc.) do not affect the products though they have an effect on crystal size. Compound 4 has a unique structure with hexanuclear nickel cluster forming 2-D layers. Magnetic measurement for 4, suggest that there are competing ferromagnetic and anti-ferromagnetic behavior with complex being anti-ferromagnetic at lower temperatures. Reaction time was reduced to less then 2 hours in microwave synthesis with higher yield. Magnetic studies are underway to understand interactions within these complexes .

Observations

[Ni6(OH)6(trans-1,4-CHDC)3(H2O)6].2H2O

Space Group: R3-c

[Ni3(OH)2(trans-1,4-CHDC)2(H2O)4].4H2O

Space Group: C2/m

[Ni3(OH)2(cis-1,4-CHDC)2(H2O)4].2H2O

Space Group: P21/c

Crystal Structures Magnetic Measurements

X-r

ay D

iffr

acti

on

Dat

a

Synthesis

Products were characterized by single crystal and powder XRD.

NiAc + CHDC (Hydrothermal reaction for 2 Days)

Nickel 1,4 cyclohexanedicarboxylate

Nickel 1,4-cyclohexanedicarboxylate coordination polymers –

Prashant Jain@, Russel K Feller#, Naresh Dalal@, Tony Cheetham#, and Harold W. Kroto@

@ Dept. of Chemistry & Biochemistry, Florida State University, # Materials Research Laboratory, University of California, Santa

Barbara

Synthesis, Characterization, Phase study, and Magnetic Properties

Coordination polymers or metal organic frameworks (MOFs) have very interesting topologies and important

potential applications as functional materials.

Nickel 1,4-cyclohexanedicarboxylate

Ni6(OH)6(chdcox)3(H2O)6.2H2O

Ni6(OH)6(chdcox)3(H2O)6.2H2O

Nickel 1,4-cyclohexanedicarboxylate coordination polymers – Synthesis, Characterization, Phase study, and Magnetic PropertiesPrashant Jain@, Russel K Feller#, Naresh Dalal@, Tony Cheetham#, and Harold W. Kroto@

@ Dept. of Chemistry & Biochemistry, Florida State University, # Materials Research Laboratory, University of California, Santa Barbara

Overview

Coordination polymers or metal organic frameworks are of great recent research interest due to their interesting topologies and potential applications as functional materials. Hydrothermal chemistry has been widely used for preparation of these compounds. Control of products in the hydrothermal reactions is still an exciting challenge for the chemists. Here we report the synthesis of five nickel complexes starting from identical reaction mixture. A detailed study was conducted to determine the way in which reaction conditions governed the resulting phases. Temperature and concentration were found to be the two main determining factors.

Products

Five nickel complexes were observed. Structures of three complexes were solved by single crystal XRD.

For complex 4 (space group R3-c) the temperature dependence of reciprocal of the susceptibility is linear above 60 K and obeys the Curie-Weiss law with a Weiss constant θ = -146.89 K and C = 9.43 cm3 K mol-1. The C value correspond to the six non-interacting Ni II ions (S=1) with g = 2.21. χT value at room temperature (6.33 cm3 K mol-1) is lower then an expected value (7.33 cm3 K mol-1).

Effect of reaction conditions

As shown in the reaction condition diagram, it was possible to synthesize pure complexes. Other variables (eg. solvent volume, fill volume, stirring etc.) do not affect the products though they have an effect on crystal size. Compound 4 has a unique structure with hexanuclear nickel cluster forming 2-D layers. Magnetic measurement for 4, suggest that there are competing ferromagnetic and anti-ferromagnetic behavior with complex being anti-ferromagnetic at lower temperatures. Reaction time was reduced to less then 2 hours in microwave synthesis with higher yield. Magnetic studies are underway to understand interactions within these complexes .

Observations

[Ni6(OH)6(trans-1,4-CHDC)3(H2O)6].2H2O

Space Group: R3-c

[Ni3(OH)2(trans-1,4-CHDC)2(H2O)4].4H2O

Space Group: C2/m

[Ni3(OH)2(cis-1,4-CHDC)2(H2O)4].2H2O

Space Group: P21/c

Crystal Structures Magnetic Measurements

X-r

ay D

iffr

acti

on

Dat

a

Synthesis

Products were characterized by single crystal and powder XRD.

NiAc + CHDC (Hydrothermal reaction for 2 Days)

Nickel 1,4 cyclohexanedicarboxylate

The temperature dependence of reciprocal of the susceptibility is linear above 60 K and

obeys the Curie-Weiss law

The temperature dependence of reciprocal of the susceptibility is linear above 60 K and

obeys the Curie-Weiss law

The temperature dependence of reciprocal of the susceptibility is linear above 60 K and

obeys the Curie-Weiss law

→

1/χM

The temperature dependence of reciprocal of the susceptibility is linear above 60 K and

obeys the Curie-Weiss law

The temperature dependence of reciprocal of the susceptibility is linear above 60 K and obeys the Curie-Weiss law with a Weiss constant θ = -146.89 K and C = 9.43 cm3 K mol-1.

The temperature dependence of reciprocal of the susceptibility is linear above 60 K and obeys the Curie-Weiss law with a Weiss constant θ = -146.89 K and C = 9.43 cm3 K mol-1.

→

1/χM

Functional materials are an essential part of our everyday lives.

1.silicon chip with its ever-increasing power

2.light-emitting materials at the heart of today’s telecommunications or DVD players

3.liquid crystal displays

4.magnetic materials used in recording devices.

For complex 4 (space group R3-c) the temperature dependence of reciprocal of the susceptibility is linear above 60 K and obeys the Curie-Weiss law with a Weiss constant θ = -146.89 K and C = 9.43 cm3 K mol-1. The C value correspond to the six non-interacting NiII ions (S=1) with g = 2.21. χT value at room temperature (6.33 cm3 K mol-1) is lower then an expected value (7.33 cm3 K mol-1).

Functional materials are an essential part of our everyday lives.

Functional materials are an essential part of our everyday lives.

1.silicon chip with its ever-increasing power

Functional materials are an essential part of our everyday lives.

1.silicon chip with its ever-increasing power

2.light-emitting materials at the heart of today’s telecommunications or DVD players

Functional materials are an essential part of our everyday lives.

1.silicon chip with its ever-increasing power

2.light-emitting materials at the heart of today’s telecommunications or DVD players

3.liquid crystal displays

Functional materials are an essential part of our everyday lives.

1.silicon chip with its ever-increasing power

2.light-emitting materials at the heart of today’s telecommunications or DVD players

3.liquid crystal displays

4.magnetic materials used in recording devices.

As shown in the reaction condition diagram, it was possible to synthesize pure complexes. Other variables (eg. solvent volume, fill volume, stirring etc.) do not affect the products though they have an effect on crystal size. Compound 4 has a unique structure with hexanuclear nickel cluster forming 2-D layers. Magnetic measurement for 4, suggest that there are competing ferromagnetic and anti-ferromagnetic behavior with complex being anti-ferromagnetic at lower temperatures. Reaction time was reduced to less then 2 hours in microwave synthesis with higher yield. Magnetic studies are underway to understand interactions within these complexes .

Functional materials are ubiquitous. New materials with improved functionality will be in demand in the marketplace and materials exhibiting more than one degree of functionality will appear to provide even more applications

2 D oligomer self-assembly

Hydrothermal chemistry has been widely used for preparation of these compounds. Control of products in the hydrothermal reactions is still an exciting challenge for the chemists. Here we report the synthesis of five nickel complexes starting from identical reaction mixture.

Effect of reaction conditions

100 125 150 175 200

Temperature

100 125 150 175 200

Temperature

©

©Pile of flat sheets

Nickel 1,4-cyclohexanedicarboxylate coordination polymers – Synthesis, Characterization, Phase study, and Magnetic PropertiesPrashant Jain@, Russel K Feller#, Naresh Dalal@, Tony Cheetham#, and Harold W. Kroto@

@ Dept. of Chemistry & Biochemistry, Florida State University, # Materials Research Laboratory, University of California, Santa Barbara

Overview

Coordination polymers or metal organic frameworks are of great recent research interest due to their interesting topologies and potential applications as functional materials. Hydrothermal chemistry has been widely used for preparation of these compounds. Control of products in the hydrothermal reactions is still an exciting challenge for the chemists. Here we report the synthesis of five nickel complexes starting from identical reaction mixture. A detailed study was conducted to determine the way in which reaction conditions governed the resulting phases. Temperature and concentration were found to be the two main determining factors.

Products

Five nickel complexes were observed. Structures of three complexes were solved by single crystal XRD.

For complex 4 (space group R3-c) the temperature dependence of reciprocal of the susceptibility is linear above 60 K and obeys the Curie-Weiss law with a Weiss constant θ = -146.89 K and C = 9.43 cm3 K mol-1. The C value correspond to the six non-interacting Ni II ions (S=1) with g = 2.21. χT value at room temperature (6.33 cm3 K mol-1) is lower then an expected value (7.33 cm3 K mol-1).

Effect of reaction conditions

As shown in the reaction condition diagram, it was possible to synthesize pure complexes. Other variables (eg. solvent volume, fill volume, stirring etc.) do not affect the products though they have an effect on crystal size. Compound 4 has a unique structure with hexanuclear nickel cluster forming 2-D layers. Magnetic measurement for 4, suggest that there are competing ferromagnetic and anti-ferromagnetic behavior with complex being anti-ferromagnetic at lower temperatures. Reaction time was reduced to less then 2 hours in microwave synthesis with higher yield. Magnetic studies are underway to understand interactions within these complexes .

Observations

[Ni6(OH)6(trans-1,4-CHDC)3(H2O)6].2H2O

Space Group: R3-c

[Ni3(OH)2(trans-1,4-CHDC)2(H2O)4].4H2O

Space Group: C2/m

[Ni3(OH)2(cis-1,4-CHDC)2(H2O)4].2H2O

Space Group: P21/c

Crystal Structures Magnetic Measurements

X-r

ay D

iffr

acti

on

Dat

a

Synthesis

Products were characterized by single crystal and powder XRD.

NiAc + CHDC (Hydrothermal reaction for 2 Days)

Nickel 1,4 cyclohexanedicarboxylate

Functional materials are ubiquitous. New materials with improved functionality will be in demand in the marketplace and materials exhibiting more than one degree of functionality will appear to provide even more applications

As shown in the reaction condition diagram, it was possible to synthesize pure complexes. Other variables (eg. solvent volume, fill volume, stirring etc.) do not affect the products though they have an effect on crystal size. Compound 4 has a unique structure with hexanuclear nickel cluster forming 2-D layers. Magnetic measurement for 4, suggest that there are competing ferromagnetic and anti-ferromagnetic behavior with complex being anti-ferromagnetic at lower temperatures. Reaction time was reduced to less then 2 hours in microwave synthesis with higher yield. Magnetic studies are underway to understand interactions within these complexes .

Observations

Hydrothermal chemistry has been widely used for preparation of these compounds. Control of products in the hydrothermal reactions is still an exciting challenge for the chemists. Here we report the synthesis of five nickel complexes starting from identical reaction mixture.

A detailed study was conducted to determine the way in which reaction conditions governed the resulting phases. Temperature and concentration were found to be the two main determining factors.

OverviewCoordination polymers or metal organic frameworks (MOFs) are of great recent research interest due to their interesting topologies and potential applications as functional materials.

Hydrothermal chemistry has been widely used for preparation of these compounds. Control of products in the hydrothermal reactions is still an exciting challenge for the chemists. Here we report the synthesis of five nickel complexes starting from identical reaction mixture. A detailed study was conducted to determine the way in which reaction conditions governed the resulting phases. Temperature and concentration were found to be the two main determining factors.